Table of contents

[binding_recto] [interleaf] [interleaf] [interleaf]
[titlePage_recto]
THE
INSTITUTIONS
OF
PHYSIOLOGY,
TRANSLATED FROM THE LATIN OF THE THIRD AND LAST
EDITION.
AND
Supplied with numerous and extensive notes,
BY
JOHN ELLIOTSON, M.D.
Member of Jesus College, Cambridge; the Royal College of Physicians, London; the
Medico-Chirurgical Society of London; Member, and formerly President of
the Royal Medical Society of Edinburgh.

SECOND EDITION.

Quaeramus optima, nec protinus se offerentibus gaudeamus; adlubeatur judicium
inventis, dispositio probatis.
(Quintilian.)

PHILADELPHIA:
PUBLISHED BY BENJAMIN WARNER, AND FOR SALE AT [...]
PHILADELPHIA, AND RICHMOND, VIRGINIA


1817.
[titlePage_verso]

THE
TRANSLATOR’S PREFACE.

[[iii]]

The highly flattering manner in which the Edition which
I last year published of this work, was received, has both en-
couraged and compelled me this year to prepare a second
Edition.

The translation has been revised, all Blumenbach’s referen-
ces inserted, and my own notes and references increased to a
considerable extent. In the latter, the progress of Physiolo-
gical science since 1810, when the last Edition of Blumen-
bach’s work was published, is detailed, and many points are
treated of at large which could not, consistently with Blumen-
bach’s design, be more than briefly mentioned in the original.
The last note, – upon the characteristics and varieties of man-
kind, is an independent addition.

No one can be more sensible than myself to the imperfec-
tions of my performance. In excuse I must urge the prodi-
gious extent and variety of my subject, and the short period
allowed me through the rapid sale of the first Edition and
the importunities of my Bookseller for the second.

No one will ever listen more readily to friendly criticism, or
more readily smile at and forgive the suggestions of ill nature.

Grafton Street, Bond Street.
Dec. 1816.

THE AUTHOR’S PREFACE
TO THE
LAST EDITION.

[[iv]]

Whenever my booksellers have informed me that a
new edition of any of my works was required, I have always
gladly seized the opportunity of correcting inaccuracies,
arising either from carelessness or the imperfection of human
nature; of adding in some places and altering in others; in
short, of sending forth the production of my abilities in a
more finished state.

In preparing this new edition of my Institutions of
Physiology for the press, the same anxious wish has been
considerably heightened by the importance of the subject, and
by the approbation evidently bestowed upon the last edition,
from its translation into our own language, into Spanish,
French, English, Dutch, and Russian, not to mention other
proofs of its favourable reception. I have endeavoured,
therefore, to enrich it not so much with an addition of pages,
as of various matter; to arrange the heads in a more natural
order; and to render the Whole as useful to students as
possible.

September 10, 1810.

THE AUTHOR’S PREFACE
TO THE
FIRST EDITION.

[[v]]

The same considerations which led Boerhaave, and after
him Haller, to write their Compendiums of Physiology, in-
duced the author to compose these Institutions.

The former says, ‘“that a teacher succeeds better in com-
menting upon his own thoughts, than upon a work written
by another: – that his doctrine will be clearer, and his lan-
guage generally animated,”’ &c.*

The latter, ‘“That although he formerly used Boerhaave’s
work as a text-book, he afterwards lectured upon one written
by himself, because, since the time of Boerhaave, anatomy
has been so improved as to become almost a new science.”’

What Haller said at that period respecting anatomy, will
be allowed to apply much more forcibly at present to physi-
ology, by any one who considers the most important parts of
the science, – the principal purpose of respiration, animal
heat, digestion, the true nature and use of the bile, the func-
tion of generation, &c.

More, therefore, must be ascribed to the age than to the
[Seite vi] author, if in these Institutions, after so many modern physi-
ological discoveries, he delivers doctrines more sound and
natural than it was in the power of his most meritorious pre-
decessors to deliver.

Whatever he can claim as his own, whether really new or
only explained in a new manner, will be easily discovered by
the learned and impartial reader; especially from the notes,
in which he has treated some of these subjects rather more
minutely than, in the text, was compatible with the concise-
ness of his plan.

He has been at great pains in arranging the subjects, so
that the sections might succeed naturally and easily, and
arise, as it were, one out of another.

He has not quoted a dry farrago of books, but a select
number, in doing which, he has wished both to point out to
students some excellent authors not commonly known, es-
pecially those who have professedly treated on particular
branches of the subject, and to open, besides medical sources
of information, others not yet applied, he conceives, to Phy-
siology as they deserve.

His grand object has been to deliver, in a faithful, concise,
and intelligible manner, the principles of a science inferior
in beauty, importance, and utility, to no part of medicine, if
the words prefixed by the immortal Galen to his Methodus
Medendi,
are, as they most certainly are, true, – ‘“The mag-
nitude of a disease is in proportion to its deviation from the
healthy state; and the extent of this deviation can be ascer-
tained by him only who is perfectly acquainted with the
healthy state.”’

CONTENTS.

[[vii]]

sect.

page.

The translator’s notes are annexed each to the section
to which its subject respectively belongs.

The note on the characteristics and varieties of man-
kind begins at 376

THE
INSTITUTIONS
OF
PHYSIOLOGY. SECT. I.
OF THE LIVING HUMAN BODY IN GENERAL.

[Seite 1]

1. In the living human body, regarded as a peculiar or-
ganization, there are three objects of consideration.*

The materials of its subsistence, afforded by the fluids;

The structure of the solids, containing the fluids;

Lastly, and principally, the vital powers, by which the
solids are enabled to receive the influence of the fluids –
to propel the fluids – and perform various other motions;
[Seite 2] and which, as they, in a certain sense, constitute the essence
of the living machine in general, so also are of very different
orders: some being common to animals and vegetables, and
some peculiar to animals, and intimately connected with the
mental faculties.

2. But these three, although really distinct, and there-
fore distinctly considered by us, are so closely related in the
living system, (the phenomena, conditions, and laws of whose
functions, in the healthy state, are the object of physiology,)
that no one can be contemplated, but in its relation to the
rest.

For the materials of the body, although originally fluid,
are naturally disposed to become solid; and, on the other
hand, the solids, besides having been formed from the fluids,
abound, however dry they may appear, in various kinds of
fluid constituents, both liquid and aeriform: lastly, it may
probably be affirmed that no fibril, during life, is detitute
of vital power.

3. We shall now examine each of these separately; and
first, the materials afforded by the fluids, which form
the fundamental and most considerable portion of our bo-
dies.*

SECT. II.
OF THE FLUIDS IN GENERAL, AND PARTICULARLY OF THE
BLOOD.

[Seite 3]

4. The fluids of the body may be conveniently reduced
to three classes.

A. The crude; viz. the chyle, contained in the primae vise,
and destined to become blood; also, matters absorbed on the
surface, and destined to be conveyed to the chyle.

B. The blood itself.

C. Those secreted from the blood, whether inert and ex-
crementitious, like the urine; or intended for certain pur-
poses in the economy: the latter may be permanently liquid,
as the bile – or disposed to solidity, as the osseous and other
plastic juices.

5. Of the first and third of these classes, we shall here-
after speak, in treating of chylosis, secretion, and the other
functions to which each fluid appertains. At present our
attention shall be devoted to the blood,* the chief and pri-
mary fluid – the vehicle of those successions of oxygenous
(A) and carbonaceous particles, which cease only with life –
the nourisher of the frame – the source of almost every fluid –
that into which the crude fluid is converted, and from which
all the secretions are derived; and which, with the excep-
tion of some exsangueous parts, as the epidermis, the arach-
[Seite 4] noid, the amnion, &c. the virtreous substance of the teeth,
the body of the chrystaline lens, &c. is universally dif-
fused through the system, in various proportions, indeed,
according to the various natures of the similar parts, to use
the language of the ancients,* v.c. abudantly in the muscles
and glands, sparingly in the tendons and cartilages.

6. The blood is a peculiar fluid, of a well known colour
and remarkable odour; its taste rather salt and nauseous;
its temperature about 96° of Fahrenheit; glutinous to the
touch; its specific gravity, though different in different in-
dividuals, may be generally estimated as 1050, water being
1000: when first drawn, and received into a vessel, it exhi-
bits the following appearances.

7. At first, especially while still warm, it emits a
vapour which has of late been denominated an animal
gas, and shewn to consist of hydrogen and carbon, sus-
pended by caloric.§ This, if collected, forms drops, re-
[Seite 5] sembling dew of a watery nature, but endowed with a
nidorous odour, most remarkable in the blood of carnivo-
rous animals, peculiar and truly animal. Much of this
watery liquor still remains united with the other parts of the
blood.

8. In the mean time the blood, when its temperature
has fallen to about 78°, begins to separate into two por-
tions. A coagulum is formed, from the surface of which,
as it were, exudes a fluid of a yellowish slightly red
colour, denominated serum: the more abundantly this
exudes, the greater is the contraction of the glutinous
coagulum, which has received the appellations of crassa-
mentum;
and, from some resemblance to the liver, in colour
and texture, of hepar sanguineum; of placenta; and from
the circumstance of its being surrounded by the serum, of
insula.

9. The crassamentum may, by agitation, or repeated
ablution, be easily separated into two constituent parts:
into the cruor, which imparted to the blood its purple
colour, and into the lymph, which on washing is forsaken
by the cruor, and called, from its-greater solidity, the
basis of the crassamentum. The stronger affinity of the
cruor for the lymph than for the serum, is proved by the
necessity of violence to effect their disunion (B). By the
removal of the cruor the lymph becomes gradually paler, till
it is at length merely a white tenacious coagulum.

10. Besides the watery fluid first mentioned, there are
the three constituents of the blood, viz. the serum, the
cruor, and the lymph: we shall presently treat of each
[Seite 6] more particularly. These, however, while recent, and in
possession of their native heat, are intimately mixed, and
form an equable, homogeneous fluid. Their relative pro-
portion is astonishingly diversified, according to age, tem-
perament, diet, and similar circumstances, which constitute
the peculiar health of each individual.

11. The serum is a fluid, sui generis; the chief cause
of the viscidity of the blood, and easily separable by art
into different constituent principles. If subjected to a
temperature of 150° Fahr. a portion is converted into a
white scissile substance, resembling boiled albumen: the
rest exhibits besides the watery fluid so often mentioned,
a turbid fluid of a gelatinous, or rather mucous* nature,
which on cooling appears a tremulous coagulum. The
serum is remarkable for the quantity of soda (mineral al-
kali) which it contains. (C)

12. The cruor is marked by many irregularities, both in
the colour and the figure of its particles. It consists of
globules, which in recent blood are of a constant form
and size, and said to be 1/300 of an inch in diameter.
Their form, indeed, has been a subject of dispute; but I
am disposed to consider it as much more simple than
some writers of great celebrity have imagined. I have
always found it globular, and could never discover the
lenticular shape, which some have asserted that they re-
marked.

It has been likewise advanced, that the globules change
their form, while passing through a vessel of very small
capacity; that, from being spherical, they become oval;
and when they have emerged into a vessel of larger area,
[Seite 7] that they again resume their globular shape.* This, although
I would by no means deny it, I cannot conceive to occur du-
ring the tranquil and healthy motion of the blood, but should
refer it to a spasm of the small vessels.

Their globular figure can be seen in a living animal
only, or in blood very recently drawn: for they are
soon unobservable, becoming a shapeless mass which
resembles serum in every circumstance, excepting co-
lour.

Their colour is red, and from it is derived the colour of
the blood. In intensity it varies infinitely; paler in animals
which have been poorly nourished or have suffered from
haemorrhage; more florid, when oxygenized, (or rendered
arterial, to use the common phrase) by exposure ei-
ther to atmospheric air, or more especially, oxygen;
darker when carbonized (in common language render-
ed venous) by exposure to carbonic acid gas, or to hydro-
gen. The redness is most probably to be ascribed to the
[Seite 8] oxide of iron,* the quantity of which, however, is so minute,
that it has been most variously estimated (D).

14. The last constituent principle of the blood to be no-
ticed, is the plastic lymph, formerly confounded with the
serum. This has been called the basis of the crassamentum,
the glutinous part, the fibre or fibrous matter of the blood,
and, like the caseous part of milk, and the gluten of vegeta-
bles, been discovered by late analysis to abound in carbon
and azote (E).

15. It is properly denomiated plastic, because it affords
the chief materials from which the similar parts, especially
the muscles, are immediately produced; nourishes the body
throughout life, repairs wounds and fractures in an ex-
traordinary manner, fills up the areae of large divided
blood vessels, and forms those concretions which accompany
inflammations, and that remarkable decidous membrane
found in the recently impregnated uterus for the attachment
of the ovum.

16. Thus much have we said, respecting the constituent
parts and nature of the blood, the most important fluid of
the animal machine, – a fluid, which excites the heart to
[Seite 9] contraction, which distributes oxygen to every part, and
conveys the carbon to the excretory vessels, giving rise,
by this change, to animal heat; which originally supplies
the materials of the solids, and afterwards their nourish-
ment;
from which all the fluids, with the exception of
the crude (4.) are secreted and derived. Of the multifa-
rious importance of the blood, we shall speak particularly
hereafter.



NOTES.

(A) The blood is not at present believed to absorb any
oxygen during respiration. See note (C) to Sect. viii.

(B) The red particles, or cruor, are merely suspended
in the serum, as Leeuwenhoek and Hartsoeker long since
proved, for if, when separated, they are triturated in
serum, part of them is taken up, and the serum assumes a
red colour; but if the fluid is allowed to settle in a cylin-
drical glass, they slowly precipitate themselves to the
bottom, and the serum above becomes clear, as before.
The serum easily separates on the coagulation of the
lymph; the colouring part does not fall to the bottom
before the lymph coagulating envelopes it and prevents
its separation: but if the lymph coagulate slowly, as in
the phlogistic diathesis, the greater specific gravity of the
cruor detaches it very considerably from the lymph,
which remains colourless above, constituting what is
called the inflammatory coat, crust or buff. Berzelius
even believes the lymph to be in a state of solution in the
serum, while the cruor is simply suspended in this solu-
[Seite 10] tion, but the separation of the serum in dropsy, vesication,
&c. led Mr. Hunter to a different conclusion. View of the
present State and Progress of Animal Chymistry
by Jöns
Jacob Berzelius, M.D. &c. Translated by Dr. Brunnmark,
1813, p. 23. Hunter On the Blood, &c 4to. p. 18.

(C) The coagulable part of serum is albumen; that which
remains fluid is called serosity, – a name given it by Cullen,
and contains no jelly, as the French chymists asserted, but
an animal matter different from both jelly and albumen,
with a minute portion of albumen and fibrin, a little free
soda, muriate, lactate,* and phosphate of soda, and muriate
of potash, with 905/1000 of water.

(D) It has been generally supposed that iron existed in
the red particles of the blood as a subphosphate. Berzelius
informs us that serum, although able to dissolve a small
portion of the oxydes, not indeed of the phosphates of iron,
does not acquire a red colour by their addition; and that he
has never discovered iron nor lime in the entire blood, al-
though both are so abundant in its ashes; and concludes that
the blood contains the elements of phosphate of iron and
of lime, and of carbonate of lime, and also of phosphate of
magnesia, united in a manner different from their combina-
tion in the salts.

(E) Oxygen and hydrogen also exist in fibrin. The
fibrin, albumen and colouring matter afford, on decom-
postion, the same saline and gaseous products. Berzelius
[Seite 11] views them all three as modifications of the same substance.
Albumen has a greater proportion of oxygen than fibrin, and
has sulphur for a constituent part, which consequently can-
not be detected while the albumen is entire, any more than
the iron while the cruor is entire. The chief differences be-
tween the colouring matter and fibrin are colour; the sponta-
neous coagulation of fibrin at all temperatures, while the co-
louring matter may be dried without losing its solubility in wa-
ter, and becomes insoluble only at a certain temperature; and
the peculiarity of the latter, of not diminishing in volume,
like fibrin, during exsiccation. – Berzelius, l. c.

SECT. III.
OF THE SOLIDS IN GENERAL, AND OF THE MUCOUS WEB IN PARTI-
CULAR.

[Seite 12]

17. The solids* are derived from the fluids. In the first
rudiments of the gelatinous embryo, they gradually com-
mence in their respective situations, and differ infinitely in
their degrees of cohesion, from the soft and almost pulpy
medullary matter of the brain, to the vitreous substance of
the corona of the teeth.

18. Besides the gelatinous (11) and glutinous (15) parts
of the solids, earth enters more or less into their composition,
and is principally lime united with phosphoric acid. The
bones possess this in the greatest abundance, particu-
larly in advanced age, whereas in childhood the gelatinous
matter abounds.

19. With respect to texture, a great part of the solids
consist of fibres more or less parallel. This may be ob-
served in the bones, especially of foetuses, in the mus-
[Seite 13] cles, tendons, ligaments, aponeuroses, and in certain mem-
branes, as the dura mater, &c.

20. In other parts no fibres can be discovered, but the
texture is peculiar, called parenchyma, from the time of
Erasistratus, and differing in different viscera, especially
the secreting, – of one kind in the liver, of another in the
kidneys.

21. But in all the structures, whether fibrous or paren-
chymatous, there is interwoven a general mucous web,*
commonly but improperly styled cellular, because it rather
is continuous, equal, tenacious, ductile, sub-pellucid, and
glutinous. By handling, it is easily converted into a cellu-
lar and vesicular membrane, and demands a place among
the most important and remarkable constituents of the bo-
dy. (A.)

22. For, in the first place, many solid parts, v.c. most
membranes and cartilages, may by long continued mace-
ration be resolved into it alone. With some it is so inti-
mately united, as to afford a receptacle and support for
other constituents: v.c. the hardest bones consisted at
first of cartilage, which was originally condensed mucous
membrane; but since become distended by the effusion of
bony matter into its substance, which is rendered more lax
and cellular. In fact, it is universally present in the solids,
if we except the epidermis, nails, and hairs, and the vi-
treous exterior of the corona of the teeth, in which I have
never been able to discover it by employing the strongest
acid.

[Seite 14]

23. To the muscles and membranes especially it serves for
separation from other parts; to the vessels and nerves for
support; and to every part it acts as the common medium of
connection.

24. From these facts, two inferences may be drawn. First:
That this membrane is so fundamental a constituent of our
structure, that, were every other part removed, the body
would still retain its form.

Secondly: That it forms a connection between all parts of
the system, however different from each other in nature, or
remote in situation: – a circumstance worthy of attention, as
putting an end to the verbal disputes respecting the continu-
ation of membranes, and affording an explanation of many
morbid phenomena.

25. As most of the solids owe their existence to this mem-
brane, so again its origin is derived from the lymph of the
blood. I have found the lymph changed into this mem-
brane, when transuded on the surface of inflamed lungs, and
by forming false membranes, it afterwards unites these organs
to the pleura.

26. We shall now consider some varieties of this mem-
brane. In general, it is more delicate, caeteris paribus, in
man than in animals, – a distinguishing prerogative, by
which our sense is rendered more delicate, and our mo-
tions and other functions more perfect.* Among dif-
ferent individuals, it varies much in laxity and firmness,
according to age, sex, temperament, mode of life, climate,
&c.

Finally, it varies in different parts; more lax in the pal-
[Seite 15] pebrae and preputium, and behind the fraenum of the tongue;
less so round the ears.

27. Besides the purposes before mentioned, (22, 23) it is
destined for the reception of several kinds of fluids. Its
chief use in this respect is to receive that serous halitus
which moistens and lubricates every part. This, when
formed by the blood vessels, it imbibes like a sponge, and
delivers over to the lymphatics, thus constituting the grand
connection between these two systems of vessels.

28. In certain parts its office is to contain peculiar fluids,
v.c. in the eye, existing as the vitreous membrane, it con-
tains the vitreous humour: in the bones, as the medullary
membrane (improperly denominated internal periosteum,)
the marrow; in soft parts, it is in great abundance, and con-
tains the rest of the fat, of which we shall speak hereafter.



NOTE.

(A) The generally received appellation of cellular mem-
brane
appears preferable to that of mucous web adopted by Blu-
menbach from Bordeu (Recherches sur le tissu Muqueux,)
and especially in this work, as our author (par. 40) suggests
the title of vis cellulosa for the contractile power of the mem-
brane.

SECT. IV.
OF THE VITAL POWERS IN GENERAL, AND PARTICULARLY OF
CONTRACTILITY.

[Seite 16]

29. Hitherto we have spoken of the solids, as the con-
stituents of the system; we now shall view them as endowed
with vitality, – capable of receiving the agency of stimuli,
and of performing motions.

30. Although vitality* is one of those subjects which are
more easily known than defined, and usually indeed render-
ed obscure rather than illustrated by an attempt at defini-
tion, its effects are sufficiently manifest, and ascribable to pe-
culiar powers only. The epithet vital is given to these
powers, because on them so much depend the actions of the
body during life, and of those parts which for a short time
after death preserve their vitality, that they are not re-
ferrible to any qualities merely physical, chemical, or me-
chanical.

31. The latter qualities, however, are of great impor-
tance in our economy. By physical powers, dependent
on the density and figure of the humours of the eye,
the rays of light are refracted to the axis; by mechanical,
the epiglottis is elastic; by chemical affinity, the changes
of respiration are effected. But the perfect difference of
[Seite 17] these dead powers from those which we are now about to
examine, is evident from the slightest comparison of an or-
ganized economy with any inorganic body, in which these
inanimate powers are equally strong.

32. Indeed the vital powers are most conspicuously mani-
fested by their resistance and superiority to the others;
v.c. during life, they so strongly oppose the chymical affini-
ties which induce putrefaction, that Stahl and his followers
referred their notion of life to this antiseptic property;*
they so far exceed the force of gravity, that, according to
the celebrated problem of Borelli, a dead muscle would be
broken asunder by the very same weight, which, if alive, it
could easily raise, &c.

33. As on the one hand, the vital properties are com-
pletely different from the properties of dead matter, so, on
the other, they must be carefully distinguished from the
mental faculties which will form the subject of the next
chapter: between them, however, there exists an intimate
and various relation observable in many phenomena, but
especially in the diversity of temperament.

34. The vital energy is the very basis of physiology, and
has therefore been always noticed, though under different
appellations. The titles of impetum faciens, innate heat,
archaeus, vital spirit, brute life, head of the nervous system,
active thinking principle, vital tonic attraction, have been
bestowed upon it by different authors.

35. Nor has there been less variety in the notions and
[Seite 18] definitions to which it has given rise; though in this one
point all have agreed, – that its nature and causes are most
obscure. (A.)

36. As to the question so long agitated by physiologists,
whether the diversity of the phenomena exhibited in the
similar parts of the living solid, are to be attributed to mo-
difications only, or to distinct species, of the vital energy,
we think it best to establish distinct orders of the vital
powers,
according to the variety of phenomena by which they
are manifested.

37. These phenomena are threefold. Organic formation
and increase; motion in the parts when formed; sensation
from the motion of certain similar parts.

38. The first requisite involved in the name and notion
of an organized body, is a determinate form designed for
certain ends. That species, therefore, of the vital powers
is most general, which produces the genital and nutritive
fluids, and prepares them for organic nature. This species
we have denominated the nisus formativus, since it is the
source of all generation, nutrition, and reproduction, in each
organized kingdom.

39. Those vital powers which are manifested (37) by
motion, properly so called, in parts already formed, may be
divided into common and proper. The common are those
belonging to similar parts which are widely distributed;
v.c. contractility to the mucous structure; irritability to
the muscular fibre. (B.) The proper are those possessed
only by individual organs, whose motions are peculiar and
characteristic.

40. Contractility is as generally distributed as the mu-
cous structure, which it may be said to animate; and
therefore would perhaps not improperly be called the vis
cellulosa.
It is characterized by a simple and not very
[Seite 19] sensible effort to contract and react upon its contents, espe-
cially upon its source of moisture, – the serous vapour and to
propel this into the lymphatic system.*

41. Irritability, we mean the irritability of Haller, is pecu-
liar to the muscles, and may be called the vis muscalaris.
It is marked by an oscillatory or tremulous motion, distin-
guished from the action of simple contractility, by being far
more permanent, and by occurring far more easily on the ap-
plication of any pretty strong stimulus.

42. Such are the common (39) moving vital powers. But
some organs differ from the rest so much in their structure,
motions and functions, as not to come under the laws
of the common orders of vital power. We must, conse-
quently, either reform the characters of these orders, insti-
tute new ones, and extend their limits, or till this be done,
separate these peculiar motions from the common orders,
and designate them by the name of vitae propriae. As
examples may be adduced, the motions of the iris; the
erection of the nipple; the motions of the fimbriae of the
Fallopian tubes; the action of the placenta, and of the womb
during labour; and probably the greater part of the function
of secretion.§

[Seite 20]

43. So much in regard to the vital powers displayed by
motion. (37, 39, 42.) We have now to speak of sensibility,
which is peculiar to the nervous medulla communicating
with the sensorium. It bears the title of vis nervea, and is
the cause of perception when irritation is excited in parts to
which it is distributed.*

44. The order which we have followed in enumerating the
vital powers, (38, 43,) is that in which they successively arise
both during our formation and after birth.

The nisus formativus must take place before we can ascer-
tain the existence of the new conception.

Then contractility is exerted in the gelatinous substance of
the embryo.

When the muscular fibres are produced, they acquire ir-
ritability.

In those few organs whose motions cannot properly be re-
ferred either to contractility or irritability, there next exists
a vita propria.

Finally, after birth, sensibility, is superadded.

45. Similar also is the order, according to which the vital
powers, both common and proper, are distributed to the or-
ganized
bodies of each kingdom.

[Seite 21]

The formative power must be most universal; without it
indeed organization cannot be conceived to exist.

Contractility likewise is common to each kingdom.

Irritability and sensibility, in the sense above explained, are
peculiar to animals.

Lastly, the vita propria is variously observable in some or-
gans, particularly the generative, both of certain animals and
vegetables. (C)

46. It is scarcely necessary to remark, that most of these
modes of vital energy, though necessarily distinguished into
orders, are intimately connected; v.c. the mucous membrane,
forming the basis and seat of contractility in so many organs,
is interwoven also with the irritable muscular fibres* and the
sensible nerves.

47. Whatever may have been the opinions of physiolo-
gists respecting the difference or identity of the vital
powers, it is universally agreed that they exist in the simi-
lar solid parts, as the ancients called them, of which the
organs or dissimilar parts are composed. But it has been
disputed, and particularly of late, whether vitality is pe-
culiar to the solids, or common also to the fluids; and the
latter being granted, whether or no the blood alone is so en-
dowed.

48. As to the first question, the whole natural history of
each organic kingdom, as far as it has hitherto been cultivat-
ed, abundantly shows that those living parts, however deli-
cate, of all known animals and vegetables, are solid; a cir-
cumstance necessarily implied in their determinate figure
destined for certain uses. For, not to speak of entire
animals (which, however simple, as worms, are neverthe-
[Seite 22] less supplied with enveloping membranes) the newly laid
egg, though at first sight merely fluid, on a more careful
examination is discovered to consist of different membranes,
of the halones, the cicatricula, &c.

Humidity is indeed necessary in the living solid, for the
exertion of vitality. But that vitality exists in the solid, as
solid, is proved by the well known instances of animalcules
and the seeds of plants, in which, although long dried, the
vital principle is so entire, that they again live and germi-
nate.

49. With respect to the supposed exclusive vitality of the
blood, I candidly confess that no argument has been adduced
in its favour since the time of Harvey, which might not, I
think, be more easily, simply, and naturally explained on the
contrary supposition.

For example, the incorruptibility of the blood during life,
is far more explicable from the perpetual changes which it
undergoes, especially in respiration.

That the blood is the material from which the living
solids are produced, is no stronger an argument of its vi-
tality, than the formation of nymphaeae and so many
other remarkable plants, would be for the vitality of
water.

It is difficult to comprehend how the coagulation of the
lymph of the blood can demonstrate its vitality. The or-
ganic formation of this lymph in generation, nutrition, and
reproduction, depends not upon the lymph itself, as
lymph, but upon the action of the nisus formativus (38) up-
on it.

50. Those who formerly contended* that the blood
[Seite 23] acquires in the lungs from the air a certain principle to be
universally distributed during circulation, for the purpose of
imparting motion, &c. to the organs, were right, if they re-
garded that principle (analogous to the oxygen of the mo-
derns) as the stimulant of the living solid; wrong, if they
regarded it as vitality itself.

51. For it is on all hands agreed, that no motion occurs
but upon the action of stimuli, to receive which action the
vital powers are naturally adapted and intended.

52. These stimuli,* however multifarious, are convenient-
ly reduced to three classes; chemical, mechanical, and men-
tal.
For the present, we shall say nothing of their various
modes of action, in some instances direct, in others indirect,
by sympathy and sensorial reaction. It is sufficient at pre-
sent to cite a few examples of functions, to which each class
of stimuli conspires: such is the increased secretion of tears,
saliva, bile, &c. and the venereal turgescence of the geni-
tals.

53. If the nature of stimuli is infinitely various, no less
so are their effects, according to their nature, intensity, or
continued and repeated application to the living solid.
Hence they are generally divided into exciting and de-
pressing.

54. The power of certain stimuli in increasing the effects
of others, is very remarkable: v.c. the power of caloric,
[Seite 24] upon which probably national temperament chiefly depends.*
That of joy, a most energetic mental stimulis is similar.
Likewise perhaps that of oxygen, (50) by whose chemical
stimulus the vital powers, particularly irritability, are greatly
excited and more disposed to react, upon the impulse of
other stimuli.

55. Not less considerable than the variety of stimuli, is
that more minute discrepancy of the different organs, and of
the same organs in different individuals, according to age,
sex, temperament, idiosyncracy, habit, mode of life, &c., to
which are owing the diversified effects of the same stimuli
upon different organs, and even upon the same in different
individuals, and upon which depends what the English have
lately termed specific irritability.§

56. Lastly, the influence of stimuli by means of sympathy,
is very extraordinary: by its means, if one part is excited,
another, frequently very remote, consents in feeling, motion,
or some peculiar function.ǁ

The primary and most extensive cause of sympathy
[Seite 25] must be referred to the nerves,* and indeed chiefly to the
sensorial reaction; so that if one nervous portion is excited,
the sensorium is affected, which reacting by means of the
nerves on another part, draws it into consent with the first,
although there exist between them no immediate nervous
connection. Such is the sympathy of the iris, when
the retina is stimulated by light; and of the diaphragm
during sneezing, when the Schneiderian membrane is ir-
ritated.

There are other examples of sympathy, in which the
nerves, if they have any, have a more remote and accessory
share; among these must be placed the sympathy along
the blood vessels, strikingly instanced between the inter-
nal mammary and epigastric arteries, especially in ad-
vanced pregnancy: that along the lymphatic vessels,§ also
most remarkable during pregnancy and suckling; and
again, that dependent on analogy of structure and function,
v.c. the sympathy of the lungs with the surface and intes-
tines. (E)

[Seite 26]

57. The vital powers will be hereafter separately con-
sidered, under the distinct heads of our subject. The nisus
formativus under the head of Generation; irritability
under that of the Muscles; sensibility under that of the
nervous System; the vita propria when occasion re-
quires.

58. Besides our former brief remarks (40) upon contrac-
tility,
a few more minute will at present be very oppor-
tune.

It prevails universally, (40) wherever the mucous tela is
discoverable.

It is consequently most abundant in parts destitute of
proper parenchyma, but composed almost entirely of mucous
tela, v.c. in certain membranes: for no one will deny their
contractility, who reflects upon the spastic motions of the
dartos, the male urethra, or the gall bladder, which during
death is always closely contracted upon any calculi it may
contain.

It appears also in those viscera which consist chiefly of
this tela, v.c. in the lungs, whose external surface we have
found on living dissection very contractile; but by no means,
as Varnierus asserts, truly irritable. (F)

The presence of contractility even in the bones, is demon-
strated by the shrinking of the alveoli after the loss of the
teeth, and by the process of necrosis, by which the new bone,
when the dead portion is extricated from its cavity, contracts
to its natural size and figure. (G)

The vitreous substance of the teeth being destitute of this
tela (22) possesses no contractility, as I think appears from
the circumstance of its not shrinking, like the alveoli, if a
portion is separated by caries or fracture.

59. This contractility of the mucous tela is the chief
cause of strength, health, and beauty; since on it depend
[Seite 27] the vital elasticity and fulness,* and indeed the tone of parts,
so elegantly described by Stahl; for by its means, the mu-
cous tela, to mention one only of its functions, absorbs, du-
ring health, the serous fluid (27) like a sponge, and propels
it into the lymphatic vessels: in disease, on the contrary,
having lost its tone, it is filled with water, giving rise to aede-
ma and similar cachexies.

60. Finally, the great influence of this contractility in pro-
ducing the peculiar constitution and temperaments of indi-
viduals, is manifest from its universal presence, its close
union with the other vital powers, and from its infinite
modes and degrees in different persons.



NOTES.

(A.)
(B.)
(C.)
(D.)
} See Note to Sect. VI.

(E.) Mr. Hunter divides sympathy into general and par-
tial; such as fever from a wound, and convulsion of the
diaphragm from irritation in the nose. Partial sympathy
he subdivides into remote, contiguous and continuous, –
Where there is no evident connexion between the sympa-
thising parts, sufficient to account for the circumstance, –
where there is proximity of the sympathising parts, – and
where, as most commonly, the sympathising parts are conti-
nuous.

[Seite 28]

Bichat’s division is much better.* It cannot be under-
stood, indeed, till after the perusal of the note to the sixth
section. He considers sympathy as affecting either animal
sensibility or contractility, or organic sensibility or con-
tractility. Sympathy does not arise from nervous com-
munication, because it frequently happens that no particular
nervous communications of sympathising parts are discover-
able, while remarkable ones exist between other parts not
disposed to sympathise. Sympathy of animal contractility
occurs only when the nerves, connecting the affected muscles
with the brain, are entire; when they were divided by Bi-
chat, the convulsions in the corresponding muscles ceased.
The sympathies of the organic functions are never ascriba-
ble, as many might imagine, to continuity of surface; for
after dividing the aesophagus of a dog, Bichat produced vo-
miting equally as before, on irritating the fauces.

(F) Our author here, as in paragraph 135, means the pul-
monary portion of the pleura, and very properly regards this
and other serous membranes, as condensed cellular sub-
stance; that is, as a substance not originally cellular and now
condensed, but of the same nature with the cellular mem-
brane, though much more compact. Consult Bichat’s Traité
des Membranes.

(G) See note to sect. 6.

SECT. V.
OF THE MENTAL FACULTIES.

[Seite 29]

61. Man, whom we have found possessed of a body,
answering completely both in matter and texture, as well
as vital powers, the purposes of its formation, is endowed
likewise with a mind, a ‘“divinae particula aurae,”’ inti-
mately connected with the body, and developing by edu-
cation and exercise various kinds of faculties, which we
shall concisely enumerate, as far as they belong to our
subject.*

62. The sensibility of the nerves, mentioned above among
the vital powers, (43) constitutes, as it were, the medium
which propagates the impressions of stimuli upon sensible
parts, and especially upon the organs of sense (to be hereaf-
ter examined,) to the sensorial portion of the brain, in such
a manner that they are perceived by the mind.

63. The mental faculty to be first enumerated, and in-
deed to be placed at the bottom of the scale, is the faculty
of perception, by means of which the mind takes cogni-
zance of impressions made upon the body, and chiefly
upon the organs of sense, and becomes furnished with
ideas.

[Seite 30]

64. This faculty is assisted by another of a higher order.
attention, which so directs the mind when excited to any
idea, that it dwells upon that idea alone, and surveys it
fully.

65. To preserve and recall the marks of ideas, is the of-
fice of memory, that part of the mind, which, in the language
of Cicero, is the guardian of the rest.

66. Imagination,* on the contrary, is that faculty of the
mind, which represents not merely the signs, but the very
images of objects in the most lively manner, as if they were
present before the eyes.

67. Abstraction forms general notions more remote from
sense.

68. Judgment compares and examines the relations of the
ideas of sense and of abstract notions.

69. Lastly reason, – the most noble and excellent of all the
faculties, draws inferences from the comparisons of the judg-
ment.

70. The combination of these constitutes the intellec-
[Seite 31] tual faculty;
but there is another order, relating to appetency,
to take the word in its most extensive meaning.

71. For since we are impelled by various internal stimuli
to provide food and other necessaries, and also to satisfy the
sexual instinct, and are impelled the more violently, in pro-
portion as imagination inflames our wishes, desires, properly
so called, are thus produced; and if, on the other hand, the
mind becomes weary of unpleasant sensations, aversions
occur.

72. Finally, that faculty which selects out of many desires
and aversions, and can at pleasure determine to perform
functions for certain purposes, is denominated volition.

73. Our order of enumeration corresponds with that of the
developement of the faculties, and with the relation in which
those termed brute, – common to man and animals, and those
more or less peculiar to man, stand to each other.



NOTE.

The great peculiarities of Gall’s Metaphysics are, that the
faculties usually regarded as distinct, are considered com-
mon; and certain faculties established which were not re-
garded as distinct. Spurzheim enumerates thirty-three dis-
tinct faculties, and the various modes of operation common
to all these, constitute judgment, memory, &c. – the distinct
faculties of former metaphysicians.

SECT. VI.
OF HEALTH AND HUMAN NATURE.

[Seite 32]

74. Since health,* which is the object of physiology,
depends upon such a harmony and equilibrium of the
matter and powers of the system, as is requisite for the
due performance of its functions, it is very evident how
the four principles examined above, contribute to its sup-
port.

75. Fluids properly prepared are the first requisite; in the
next place, solids duly formed from the fluids; then the in-
vigorating influence of the vital powers; lastly, a sound mind
in this sound body.

76. These four principles act and react perpetually upon
each other: the fluids are stimuli to the solids; these again
are calculated by their vital powers to experience the influ-
ence of these stimuli, and react upon them. In reference
to the intimate union of the mind with the body, suffice
it at present to remark, that it is far more extensive than
might at first be imagined. For instance, the influence of
the will is not contained in the narrow limits of those ac-
tions designated voluntary in the schools of physiology; and
the mind, on the other hand, is influenced by the affec-
[Seite 33] tions of the body, in many other ways than by the perceptions
of sense.*

77. From the endless variety and modification of the con-
ditions belonging to these four principles, it may be easily
understood, what great latitude must be given to the notion
of health. For since, as Celsus long ago observed, every
one has some part weaker than the rest, Galen may in this
sense assert with truth, that no one enjoys perfect health.
And even among those whom we commonly regard as in
good health, this is variously modified in each individual.

78. Upon this endless modification is founded the differ-
ence§ of temperaments; or, in other words, of the mode
and aptitude of the living solidǁ in each individual, to
[Seite 34] be affected by stimuli, especially the mental; and again,
of the mental stimuli, to be excited with greater or less
facility.

79. So various are the differences of degree and com-
bination in the temperaments, that their divisions and or-
ders may be multiplied almost without end. We shall con-
tent ourselves with the four orders commonly received.*
The sanguineous – excited most readily, but slightly: The
choleric – excited readily and violently: The melancholic
excited slowly, but more permanently: And the phlegmatic
excited with difficulty.

This division, although built by Galen upon an absurd
foundation borrowed from an imaginary depravation of the
elements of the blood, appears, if made to stand alone, both
natural and intelligible.

80. The predisposing and occasional causes of the diversi-
ty of temperaments are very numerous; v.c. hereditary ten-
dency, habit of body, climate, diet, religion, mode of life, and
luxury.

81. Besides the variety of temperaments, circumstances
peculiar to every individual, by influencing the number, as
well as the energy and vigour of the functions, increase the
latitude (77) in which the term health must be received.
In regard to age, the health of a new-born infant is different
from that of an adult; in regard to sex, it differs in a mar-
riageable virgin and an old woman past child-bearing, and
during menstruation and suckling; in regard to mode of life,
it is different in the barbarous tribes of North America, and
in effeminate Sybarites.

[Seite 35]

Moreover, in every person, custom has an extraordinary
influence* over certain functions, v.c. sleep, diet; and has
therefore acquired the name of second nature.

82. The more functions flourish simultaneously in the
body, the more considerable is its life, and vice versâ.
Hence life is greatest, when the functions have attained
their highest perfection in adult age; and least, when the
functions, although very perfect, are fewer and more slug-
gish, v.c. in the newly conceived embryo; life is for the
same reason less vigorous during sleep than during the oppo-
site state.

83. The functions have been long divided by physiolo-
gists into four classes. This division, although not unex-
ceptionable, nor exactly conformable to nature, may assist
the memory.

1. The first class comprehends the vital functions, so term-
ed, because their uninterrupted and complete performance
is necessary to life. Such are the circulation and respira-
tion.

2. The second comprehends the animal functions, by
which animals are chiefly distinguished from vegetables.
[Seite 36] Such is the connection of the mind with the body, especially
sense and muscular motion.

3. The third is the natural, by means of which the body is
nourished.

4. The fourth, the genital, intended for the propagation of
the species.

We shall now examine each of these separately, begin-
ning with the vital. (A)



NOTES.

(A) The consideration of a division as ancient as Aris-
totle, and much preferable to that which Blumenbach adopts,
will perhaps form a useful note to the eighty-third para-
graph and the greater part of the fourth section.

In this, the functions are arranged in two classes; the
animal constituting one peculiar to animals; and the vital
and natural united into another, common to vegetables and
animals under the title of organic or vital. The generative
relating in their object to the species rather than to the indi-
vidual, and of but temporary duration, may be thrown into a
separate and inferior division.

We owe the revival of this classification, and our know-
ledge of the characteristics of each class of functions, to Dr.
Philip Wilson* and Xavier Bichat, although the latter, from
[Seite 37] having published a work expressly on the subject, has re-
ceived the whole honour, both in Great Britain and on the
Continent.*

The animal functions render us feeling, thinking and wil-
ling beings; they are the actions of the senses which receive
impressions, of the brain which perceives them, reflects upon
them, and wills, of the voluntary muscles which execute the
will in regard to motion, and of the nerves which are the
agents of transmission. The brain is their central organ.
The vital or organic functions are independent of mind, and
give us simply the idea of life: they are digestion, circula-
tion, respiration, exalation, absorption, secretion, nutrition,
calorification. Their heart is their central organ.

The organs of the animal functions are double and corre-
spondent, there being on each side of the median line of the
body, either two distinct organs, as the eyes, ears, extremi-
ties, or two correspondent halves, as is the case with the
brain, spinal marrow, nose, tongue, &c.

The organs of the vital or organic functions, are in very
few instances double, or situated with their centres in the
median line and possessed of symmetrical halves: witness
the heart, stomach, liver. There are indeed two kidneys,
but they continually differ in size, figure, and situation: the
two lugs are very dissimilar.

Hence Bichat infers, that in the animal functions a
harmony of action in each organ, or each half of the
organ, is indispensable to perfection, when both organs or
sides act together; and that if such harmony do not
[Seite 38] occur, it would be better, were one organ or one half to
act alone. This is unquestionably true of the eye, but
can be supposed by analogy only with regard to the brain,
ears, &c. It certainly does not hold good in the action
of the voluntary muscles, or in the operations of the brain
or spinal marrow in willing their actions. From the du-
plicity of the organs, it also happens that one side may
cease to act without detriment to the function of the
other, while in the vital or organic class no harmony of
action is possible, and the derangement of any one part
of an organ generally affects the whole; an obstruction in
the colon disturbs the functions of the whole alimentary
canal.

The animal functions experience periodical intermissions
– sleep. The organic or vital continue incessantly, suffering
merely remissions. The blood constantly circulates, the per-
spiratory fluid is constantly secreted, the stomach has no
sooner digested one meal than we commit another to it: yet
we shall hereafter see that the actions of the heart, lungs, &c.
have daily intervals of relaxation.

The animal functions are much influenced by habit; the
vital or organic are considered by Bichat as removed from
its influence. The effects of habit on our sensations
and voluntary motions are manifest: yet I think them
equally great upon the organic functions. The operation
of food and all descriptions of ingesta is most remarkably
modified by habit; through it poisons become comparatively
innoxious, and divers bear a long suspension of respira-
tion.

Bichat regards the passions as directly influencing the
organic functions only, and springing from the state of
the organs of that class. Here he is to me perfectly un-
[Seite 39] intelligible. Vexation indeed disturbs the stomach, and fear
augments the quantity of urine; but does not vexation equally
and as directly disturb the mind? Are not, in fact, the pas-
sions a part of the mind? – a part of the animal functions?
They powerfully affect, it is true, the organic or vital func-
tions, but this shows the close connection merely between the
two classes of functions.

This connection is conspicuous in respiration, the me-
chanical part of which belongs to the animal functions,
the other to the organic; and in the alimentary actions, in
which the food is swallowed and the faeces rejected by
volition, and the digestion, &c. performed independently of
our influence, by the powers of simple life. So close in-
deed is this connection, that every organ of the animal
class is the seat of organic functions: in the voluntary
muscles, the organs of sense, and even in the brain, cir-
culation, secretion, and absorption are constantly carried
on. This connection is likewise apparent in the property
of sensibility. The vital or organic properties of the
machine are fundamentally sensibility and contractility.
In the language of Bichat there are animal sensibility and
contractility,
and organic sensibility and contractility, be-
sides the common extensibility of matter, which he terms
extensibilité de tissu, and common contractility upon the
removal of distention, – Contractilité par défaut d’extension,
confounded by Blumenbach (58. clause 5 and 6) with
purely vital contractility, and indeed greater during life
than afterwards.* Animal sensibility is accompanied by
[Seite 40] a perception in the mind, as in seeing, hearing, tasting,
smelling feeling: animal contractilicy is excited by the
volition of the mind conveyed to the voluntary muscles
by means of the nerves. Organic sensibility is attended
with no perception, and is followed by contraction totally
independent of the will; the heart feels, if we may so
speak, for physiology has no proper term for the idea, the
stimulus of the blood, and, without our influence, forth-
with contracts; the lacteals feel the stimulus of the chyle
without our knowledge, and propel it without our assist-
ance. But although we never acquire the least direct
voluntary power over the actions of organic contractility,
[Seite 41] – over the peristaltic motion of the intestines, or the con-
tractions of the blood vessels, yet every organ of the or-
ganic functions may have its organic sensibility height-
ened into animal sensibility, as inflammation, for instance
of the pleura and the joints, daily demonstrates; indeed,
in some organs of that class of functions, we invariably have
sensation; the stomach is the seat of hunger; in the lungs
we experience an uneasy sensation the moment their air is
expelled.

The nerves of the animal functions run to the brain or spi-
nal marrow; those of the organic chiefly to ganglia; but, as
might be expected, the two nervous systems have abundant
communications.

The animal functions have not only a shorter existence
than the organic from their necessity of alternate repose,
but they flourish for a shorter duration, – they do not com-
mence till birth; they decline, and in the natural course of
events, terminate earlier; the organs of sense and the mental
faculties fail before the action of the heart and capillaries.
The decay of the animal functions must, in truth be the
consequence of the decay of the organic, because there are
fundamentally in every part organic functions, – circulation,
nutrition, &c. and the perfect performance of these in the
organs of the animal functions is indispensable to the perfect
performance of the animal functions. Hence the impairment
of these organic functions, even to a small extent, will de-
range or diminish the animal functions, which thus will de-
cline while the organic functions are still in sufficient strength
for the parts to remain alive.

We thus find in every living system a class of functions,
not in themselves dependent upon mind, as perfect in the
[Seite 42] vegetable as in the animal, and pervading every part of
the system. In animals there further exist certain parts
which when endowed with the common life of other parts,
– with the organic properties, are able to perform peculiar
functions to which we give the appellation of mind: the
organ of these functions is termed brain, and by means of
nerves and medullary prolongations, it maintains a corres-
pondence with the whole machine, influenced by and influenc-
ing the most distant parts. The phenomena of the mind
have been metaphysically considered in the fifth section;
they will be examined as functions of the nervous system in
the twelfth.

The organic functions constitute life in the proper
acceptation of the word. The word life should be re-
garded, like the word attraction or repulsion, as merely an
expression of a fact. In this point of view it may be as
easily defined as any other expression. By life we gene-
rally mean the circumstance of organized matter preserv-
ing its particles in such chemical relations as to prevent
other chemical relations from inducing disorganization,
or even increasing or decreasing, by internal appropria-
tion and separation; greatly inclining to preserve a tem-
perature distinct from that of the surrounding medium;
moving certain parts of itself sensibly (as muscles) or in-
sensibly (as the capillaries) independently of mere impulse,
attraction, or repulsion, or able (as seeds) to do these
things under favourable circumstances: or if not orga-
nized (as the fluid which becomes the embryo, the blood,)
the circumstance of matter produced by an organized
body endowed with the properties above mentioned, re-
sisting the ordinary chemical influences, and being capa-
ble of directly becoming (as the female genital fluid) an or-
[Seite 43] ganized system so endowed, or of directly contributing (as
the blood) to the organized substance of an already formed
system so endowed.

That fluids are as susceptible of life as solids I cannot
doubt. There is no reason why they should not be so, al-
though a person who has not thought upon the subject
may be as unable to conceive the circumstance as a West
Indian to conceive that water may by cold become solid.
It is impossible to deny that at least the fluid which becomes
the embryo, possesses life, because it becomes an organized
being: although some may perhaps contend that the male
semen acts simply the part of a peculiar stimulus to the
living fluid of the ovarian vesicle, others that the life of the
fluid of the ovarian vesicle is afforded by the male semen.
However, Blumenbach in his Commentatio de vi vitali
sanguinis,
* grants both male and female genital fluids to
be alive, notwithstanding that he fancies his victory over
the defenders of the blood’s life so complete, that like that
of the unfortunate Carthaginian Dido, ‘“in ventos vita re-
cessit.
”’ It is as easy to conceive the blood to be alive as
the ovarian fluid. The great asserter of the life of the
blood is Mr. Hunter, and the mere adoption of the
[Seite 44] opinion by Mr. Hunter would entitle it to the utmost
respect from me who find the most ardent and independent
love of truth, and the genuine stamp of profound genius
in every passage of its works. The freedom of the blood
from putrefaction, while circulating, and its inability to
coagulate after death from arsenic, electricity and light-
ning, may, like its inability to congulate when mixed
with bile, be simply chemical phenomena, independent
of vitality. But its inability to coagulate after death
from anger or a blow on the stomach, which deprive the
muscles likewise of their usual stiffness; its accelerated
coagulation by means of heat; perhaps its diminished
coagulation by the admixture of opium; its earlier pu-
tridity when drawn from old than from young persons;
its freezing, like eggs, frogs, snails, &c. more readily
when once previously frozen (which may be supposed to
have exhausted its powers); its directly becoming the
solid organized substance of our bodies, while the food
requires various intermediate changes before it is capable
of affording nutriment; the organization (probably to a
great degree independent of the neighbouring parts) of
lymph effused from the blood; and finally the formation
of the genital fluids, one at least of which must be allowed
by all to be alive, from the blood itself; do appear to
me very strong arguments in favour of the life of the
blood,* I am inclined with Mr. Hunter to believe that
[Seite 45] the chyle is alive, and that vivification commences even in the
stomach, although I should be sorry to go the same lengths
with Albinus, who was willing to grant life even to the
excrement. For the excretions must be regarded as dead
matter, useless and foreign to the system, and they all run
with the greatest rapidity into decomposition. In retention of
urine, the surgeon always finds this fluid abominably foetid;
the faeces become so when not discharged in due time, and
the neglect of washing the surface is the source of filthiness
and disease.

The essential nature of life is an impenetrable mystery,
and no more a subject for philosophical inquiry than the es-
sential nature of attraction or of matter. We have reason
to believe that life never originates, but was granted at
the creation, and is propagated from parent to offspring;
it is the property of organized systems, producing various
effects by various kinds of organization, but not quite pecu-
liar to organized matter, because capable of being possessed
by matter in a fluid state.

The animal functions demonstrate mind. This is
seated in the brain, to which the spinal marrow, nerves, and
voluntary muscles are subservient. Mind is the func-
tion of the living brain. As I cannot conceive life any
more than attraction unless possessed by matter, so I
cannot conceive mind unless possessed by a brain endowed
with life.* I speak of terrestrial or animal mind;
with angelic and divine nature we have nothing to do,
and of them we know nothing. To call the human mind
a ray of divinity appears to me absolute nonsense.
Animals are as fully endowed with mind, – with a con-
[Seite 46] sciousness of personality, with feelings, desire and will,
as man. Observation shows that superiority of mind
in the animal creation is exactly commensurate with supe-
riority of brain; that activity of mind and brain is propor-
tional; and that as long as the brain is endowed with
life, and remains uninjured, it, like all other organs, can
perform its functions, and mind continues; but, as in
all other organs, when its life is gone, its function, mind,
is gone; when causes of disturbance affect it, its function,
mind, is affected; if originally constituted defective, its
function, mind, is defective; if fully developed, and pro-
perly acted on, its function, mind, is well performed; ac-
cordingly as it varies, is the mind also varied; and the
character of the mind agrees with the character of the body,
being equally irritable, languid, or torpid, evidently because
the brain is of the same character as the rest of the body
to which it belongs: the qualities of the mind are also
hereditary,* which they could not be, unless they de-
pended, like our other qualities, upon corporeal condi-
tions; and the mind is often disordered upon the disap-
pearance of a bodily complaint, just as other organs, be-
sides the brain, are affected under similar circumstances;
the retrocession of an eruption may affect the lungs,
causing asthma; the bowels, causing enteritis; or the brain,
causing insanity; insanity and phthisis sometimes alter-
[Seite 47] nate with each other, just like affections of other organs.*
The argument of the pious and acute Bishop Butler that
the soul is immortal and independent of matter, because in
fatal diseases the mind often remains vigorous to the last, is
perfectly groundless, for any function will remain vigorous
to the last if the organ which performs it is not the seat
of the disease, nor much connected by sympathy or in
other modes with the organ which is the seat of the disease.
The stomach often calls regularly for food, and digests it
vigorously, while the lungs are all but completely con-
sumed by ulceration. As Physiologists we should say,
that the mind must perish with the brain, as much as the
secretion of bile with the liver; and the consciousness
which we have of personality, can give us no reason to
believe ourselves distinct from earth, for this, the fly pos-
sesses equally with the philosopher about whose head it
buzzes. But although I can discover in the human mind
nothing necessarily implying immortality more than in
the minds of brutes, its immortality I firmly believe, be-
cause declared in Revelation, which reason compels me
to believe. Our immortality, while the beasts of the
field utterly perish, I cannot but regard as the free
gift of God, perfectly independent of the constitution
which he has given us. Our resurrection is not
only declared in the sacred scriptures, but with it the
moral government and order of the world, and ‘“our innate
[Seite 48] pleasing hope, our fond desire, our longing after im-
mortality, our secret dread and inward horror of falling
into nought,”’ completely harmonize. As of the essential
nature of vitality or attraction, so of the essential nature
of animal mind, we are quite ignorant. It may in another
order of things exist independently of matter, but we
know it only as a function and property of certain living
organized matter – brain, and I believe with Paley, that
when it revives after death, the brain will equally re-
vive.*

SECT. VII.
OF THE MOTION OF THE BLOOD.

[Seite 49]

84. The blood, to whose great and multifarious im-
portance in the system we have slightly alluded, (16) is
distributed, with a few exceptions, (5) into the most in-
ternal and extreme recesses. This is proved by the mi-
nute injection of the vessels, and by the well known fact,
of blood issuing from almost every part, on the slightest
scratch.

85. This purple fluid does not, like an Euripus, ebb and
flow in the same parts, as the ancients imagined, but
flows in a circular course: so that being propelled from
the heart into the arteries, it is distributed throughout the
body, and returns again to the heart through the veins.*

86. We shall, therefore, say something at present of the
vessels which contain the blood; and afterwards, of the
powers by which they propel and receive it.

87. The vessels which receive the blood from the heart,
and distribute it throughout the body, are termed arteries.
These are upon the whole less capacious than the veins;
[Seite 50] but in adult and advanced age especially, of a texture far
more solid and compact, very elastic and strong.

88. The arteries consist of three coats:*

I. The exterior, called, by Haller, the tunica cellulosa pro-
pria;
by others, the nervous, cartilaginous, tendinous, &c.
It is composed of condensed cellular membrane, externally
more lax, internally more and more compact: blood vessels
are seen creeping upon it; it gives tone and elasticity to the
arteries.

II. The middle coat consists of transverse fibres, lunated
or falciform, and almost of a fleshy nature: hence this has
the name of muscular coat, and appears to be the chief seat
of the vital powers of the arteries.

III. The inner coat lining the cavity of the arteries is high-
ly polished and smooth. This is much more distinct in the
trunks and larger branches than in the smaller vessels.

89. Every artery originates either from the pulmonary
artery (the vena arteriosa of the ancients), which proceeds
from the anterior ventricle of the heart and goes to the
lungs; or from the aorta, which proceeds from the poste-
rior ventricle and is distributed throughout the rest of the
system. These trunks divide into branches, and these again
into twigs.

90. According to the commonly received opinion, the
united capacity of the branches is greater than that of the
[Seite 51] trunk from which they arise. But I fear that this is too
general an assertion; and that the measure of the diame-
ter has been improperly confounded with that of the area.
I myself have never been able to verify it, although my ex-
periments have been frequently repeated, and made not
on vessels injected with wax, but on the undisturbed ves-
sels of recent subjects – on the innominata and its two
branches – the right carotid and subclavian; on the brachial,
and the radial and ulnar.*

The inconstancy of the proportion between the capacity
of the branches and trunks is clearly shown by the various
size of the vessels under different circumstances, v.c. by the
relative capacity of the inferior thyroid artery in the infant
and the adult; of the epigastric artery, and also of the uterine
vessels, in a virgin and a woman far advanced in pregnancy;
of the omental vessels during the repletion or vacuity of the
stomach.

91. The arteries, after innumerable divisions and im-
portant anastomoses connecting different branches, terminate
at length in the beginning of the veins. By this means, the
blood is conveyed back again to the heart. The distinction
between artery and vein at the point of union, is lost.

In the present state of our knowledge, the umbilical ves-
[Seite 52] sels are to be regarded as the only exception to the ter-
mination of arteries in veins. We shall shew that they
are connected with the uterine vessels, by the intervention of
a spongy substance, called parenchyma.

92. Another description of vessels arise universally from
the arteries, and are called colourless, from not containing pure
blood, either on account of their minuteness or their spe-
cific irritability, which causes them to reject that fluid.
These are the nutrient and other secretory vessels, of which
hereafter.

93. The blood conveyed from the heart by the arteries
is carried back by the veins.

These are very different in function and structure from the
arteries, excepting however the minutest of both systems,
which are undistinguishable.

94. The veins, excepting the pulmonary, are upon the
whole more capacious than the arteries; are more ramified;
much more irregular in their course and division; in adult
age, softer and more elastic; but still very firm and remarka-
bly expansile.

95. Their coats are so much thinner, that the blood ap-
pears through them. They are likewise less in number,
being solely a cellular external (somewhat resembling the
nervous of the arteries) and a very polished internal, also
nearly agreeing with that of the arteries.

A muscular coat exists in the largest trunks only.

96. The interior coat forms, in most veins of more than
a line in diameter, very beautiful valves, of easy plav, re-
sembling bags, generally single, frequently double, and some-
times treble, so placed, that the fundus lies towards the ori-
gin of the vein, the limbus towards the heart.

These valves are not found in some parts; not in the
[Seite 53] brain, heart, lungs, secundines, nor in the system of the vena
portae.

97. The twigs, or, more properly, the radicles of the veins,
unite into branches, and these again into six principal trunks;
viz. into the two cavae, superior and inferior: and the four
trunks of the pulmonary vein (the arteria venosa of the an-
cients.)

The vena portae is peculiar in this, that, having entered
into the liver it ramifies like an artery, and its extreme twigs
pass into the radicles of the inferior cava, thus coalescing
into a trunk.

98. That the blood may be properly distributed and cir-
culated through the arteries and veins, nature has provided
the heart;* in which the main trunks of all the blood vessels
unite, and which is the grand agent and mover of the whole
system, – supporting the chief of the vital functions with
a constant and truly wonderful power, from the second or
third week after conception, to the last moment of exist-
ence.

99. The heart alternately receives and propels the blood.
Receiving it from the body by means of the superior and
inferior vena cava, and from its own substance through the
common valvular orifice of the coronary veins, it conveys
that fluid into the anterior sinus and auricle; thence into the
corresponding ventricle, which, as well as the auricle, com-
[Seite 54] municates with both orders of its own vessels, by the open-
ings of Thebesius.*

100. From this anterior, or in reference to the heart of
some animals, right ventricle, the blood is impelled through
the pulmonary artery into the lungs: returning from which,
it enters the four pulmonary veins, and proceeds into their
common sinus and the left, or, as it is now more properly
termed, the posterior auricle.

101. It flows next into the corresponding ventricle;
and then passing into the aorta, is distributed through the
general arterial system and the coronary vessels of the
heart.

102. Having proceeded from the extreme twigs of the
general arterial system into the radicles of the veins, and
from the coronary arteries into the coronary veins, it finally
is poured into the two venae cavae, and then again pursues
the same circular course.

103. The regularity of this circular and successive motion
through the cavities of the heart is secured, and any retro-
grade motion prevented, by the valves which are placed at the
principal openings: viz. at the openings of the auricles into
the ventricles, and of the ventricles, into the pulmonary arte-
ry and aorta.

104. Thus the ring, or venous tendon, which forms the
limit of the anterior auricle and ventricle, descending into
[Seite 55] the latter cavity, becomes three tendinous valves.* These
were formerly said to have three apices, and were there-
fore called trigochline or tricuspidal: they adhere to the
fleshy pillars, or, in common language, the papillary mus-
cles.

105. In a similar manner, the limits of the posterior auri-
cle and ventricle are defined by a ring of the same kind, con-
stituting two valves, which, from their form, have obtained
the appellation of mitral.

106. At the opening of the pulmonary artery and
aorta§ are found the triple semilunar or sigmoid valves,ǁ
fleshy and elegant, but of less circumference than the
mitral.

107. It is obvious how these valves must prevent the retro-
cession of the blood into the cavae. They readily permit the
blood to pass on, but are expanded, like a sail, against it, by
any attempt at retrograde movement.

108. The texture of the heart is peculiar: fleshy, in-
deed, but very dense and compact, far different from com-
mon muscularity.** It is composed of fasciculi of fibres,
more or less oblique, here and there singularly branching
out, curiously contorted and vorticose in their direction,
[Seite 56] lying upon each other in strata, closely interwoven between
the cavities, and bound by four cartilaginous bands to the
basis of the ventricles, which are thus supported and
distinguished in their texture from the fibres of the auri-
cles.*

109. These fleshy fibres are supplied with very soft nerves
and an immense number of blood vessels, which arise from
the coronary arteries, and are so infinitely ramified, that
Ruysch described the whole structure of the heart as com-
posed of them.§

110. The heart is loosely contained in the pericardium.ǁ
This is a membraneous sac, arising from the mediastinum,
of the same figure as the heart, very firm, and moistened
by an exhalation from the arteries of the heart. Its im-
portance is evinced by its existence being, in red blooded
animals, as general as that of the heart; and by only
two instances being recorded of its absence in the human sub-
ject.**

[Seite 57]

111. By this structure, the heart is adapted for perpetual
and equable motions, which are an alternate systole and dis-
astole, or contraction and relaxation of the auricles and ven-
tricles in succession.

112. Thus, as often as the auricles contract to impel the
blood of the venae cavae and pulmonary veins into the ven-
tricles, these are at the same moment relaxed, to receive the
blood: immediately afterwards, when the distended ven-
tricles are contracting to impel the blood into the two great
arteries, the auricles relax, and receive the fresh venous
supply.

113. The systole of the ventricles, upon which is said to
be spent one third of the time of the whole action of the
heart, is performed in such a way, that their external por-
tion is drawn towards their septum, and the apex of the
heart towards the base.* This at first sight seems disprov-
ed by the circumstance of the apex striking against the left
nipple, and consequently appearing elongated: a circum-
stance, however, to be attributed to the double impetus of
the blood flowing into the auricles and expelled from the
ventricles, by which the heart must be driven against that
part of the ribs. (A)

114. The impulse imparted by the heart to the blood, is
communicated to the arteries, so that every systole of the
heart is remarkably evident in those arteries which can be
explored by the fingers and exceed 1/6 of an inch in diameter,
and in those also whose pulsation can be otherwise discover-
ed, as in the eye and ear. The effect upon the arteries is
called their diastole, and is correspondent and synchronous
with the systole of the heart.

[Seite 58]

115. The quickness of the heart’s pulsations during health,
varies indefinitely; chiefly from age, but also from other con-
ditions, which at all ages form the peculiar health of an indi-
vidual; so that we can lay down no rule on this point. I
may, however, be permitted to mention the varieties which I
have found in our climate* at different ages; beginning with
the new-born infant, in which, while placidly sleeping, it is
about 140 in a minute.

Towards the end of the first year, about 124
- - - - - - - - - - - - - - - second 110
- - - - - - - - - - - - - - - third and fourth 96
When the first teeth begin to drop out 86
At puberty 80
At manhood 75
About sixty 60

In those more advanced, I have scarcely twice found it
alike.

116. The pulse is, ceteris paribus, more frequent in wo-
men than in men, and in short than in tall persons. A more
constant fact, however, is its greater slowness in cold cli-
mates. Its greater frequency after meals and coition, du-
ring continued watchfulness, exercise, or mental excitement,
is universally known. (B)

117. The heart rather than the arteries is to be regarded
as the source of these varieties.

Its action continues in this manner till death, and then
[Seite 59] all its parts do not, at once cease to act; but the right por-
tion, for a short period, survives the left.*

For since the collapsed state of the lungs impedes the
course of the blood from the right side, and the veins must
be turgid with the blood just driven into them from the
arteries, it cannot but happen that this blood, driving against
the right auricle, must excite it to resistance for some time
after the death of the left portion of the heart.

118. This congestion on the right side of the heart,
affords an explanation of the small quantity of blood found
in the large branches of the aorta. Weiss, and after him
Sabatier, ascribe to this cause likewise the comparatively
larger size§ of the right auricle and ventricle in the adult
dead subject especially.

119. The motion of the blood is performed by these
two orders of vessels, in conjunction with the heart. Its
celerity in health cannot be determined: for it varies not
only in different persons, but in different parts of the
same person. Generally, the blood moves more slowly
in the veins than in the arteries, and in the small vessels
[Seite 60] then in the large trunks. But these differences have been
overrated by physiologists.

The mean velocity of the blood flowing into the aorta,
is usually estimated at eight inches for each pulsation, or at
fifty feet in a minute.

120. Some have affirmed that the globules of the cruor
move more in the axis of the vessels, and with greater
rapidity, than the other constituents of the blood. I know
not whether this rests on any satisfactory experiment, or
whether upon an improper application of the laws of hydrau-
lics; improper, because it is absurd to refer the motion of
the blood through living canals, to the mere mechanical
laws of water moving in a hydraulic machine. I have ne-
ver observed this peculiarity of the globules. My persua-
sion is still more certain that the globules pass on with the
other constituents of the blood, and are not rotated around
their own axis, – that besides the progressive, there is no in-
testine
motion in the blood; although indeed there can be
no doubt, that the elements of this fluid are occasionally
divided, where it is variously impelled according to the
different direction, division, and anastomoses of the ves-
sels.

121. The powers of the sanguiferous system are now to
be examined; first, those of the heart, by far the greatest of
all; afterwards, those which are only subsidiary, though in-
deed highly useful.

122. That the powers of the heart cannot be accurately
calculated is clear, upon reflecting that neither the volume of
the blood projected at each pulsation, nor the celerity nor
distance of its projection, much less the obstacles to the
powers of the heart, can be accurately determined.

123. A rough calculation may be made by comparing
[Seite 61] every probable conjecture; v.c. it the mean bulk of the
blood is considered as 10 pounds, or 120 ounces; the pulsa-
tions 75 in a minute, or 4500 iu an hour; and the quanti-
ty of blood expelled from the left ventricle on each contrac-
tion, as two ounces; it follows that all the blood must pass
through the heart 75 times every hour. The impetus of the
blood passing from the heart, may be conceived by the vio-
lence and altitude of the stream projected from a wounded
artery, large and near the heart. I have seen the blood
driven to the distance of at least five feet from the carotid of
an adult and robust man.*

124. This wonderful, and, while life remains, constant,
strength of the heart, is universally allowed to depend on its
irritability, (41) in which it very far surpasses, especially in
continuance, (98) every other muscular part.

[Seite 62]

That the parietes of the cavities are excited to contraction
by the stimulus of the blood, is proved by the experiment of
Haller, who lengthened at pleasure the motion of either side
of the heart, by affording it the stimulus of the blood for a
longer period than the other.*

125. Since a supply of nerves and blood is requisite to
the action of the voluntary muscles, it has been inquired
whether these are requisite to the heart also.

The great influence of the nerves over the heart, is de-
monstrated by the size of the cardiac nerves, and by the
great sympathy between the heart and most functions, how-
ever different. A convincing proof of this, is the momentary
sympathy of the heart during the most perfect health
with the passions, and with the primae viae under various
disorders. But the great importance of the blood to the irri-
tability of the heart, is evident by the great abundance of
vessels in its muscular substance.

Nevertheless it is very probable, that the importance of the
nerves in this respect is greater in the voluntary muscles, and
of the blood in the heart.

[Seite 63]

126. Besides these powers of the heart, there is another
which is mechanical, dependent on structure, greatly con-
tributing, in all probability, to sustain the circulation. For
when the blood is expelled from the contracted cavities,
a vacuum takes place, into which, according to the com-
mon laws of derivation, the neighbouring blood must rush,
being prevented, by means of the valves, from regurgita-
ting.* (D)

127. We must now inquire, what powers are possessed
by other organs in assisting the circulation. The existence
and ability of some secondary powers to assist, or even in
some cases to compensate for the action of the heart, are
proved by several arguments: v.c. the blood moves in
some parts to which the influence of the heart cannot reach,
– in the vena portae and placenta; not to mention instances
of the absence of the heart.

128. The principal of these powers is the function of
the arteries, not easy indeed to be clearly understood and
demonstrated. 1. They have a muscular coat (E). 2. That
they are irritable, has been proved by repeated experi-
ments. 3. The size of the soft nerves arising from the
[Seite 64] sympathetic, and surrounding the larger arterial branches,
particularly in the lower part of the abdomen,* argues the
importance of these vessels in assisting the motion of the
blood.

129. The arteries pulsate, and indeed violently, so that
if, v.c. we place one leg over the other knee, we find not
only that it, but even a much greater weight, may be raised
by the pulsation of the popliteal. Hence an alternate systole
and diastole, corresponding with those of the heart, have
long been assigned to them. But this, although commonly
believed on the evidence of sense, is open to much question:
it may be asked, especially, whether this pulsation is re-
ferable to the power of the artery, or only to the impulse
given by the heart to the blood propelled into the aorta.

130. And indeed after all, it appears, that the diastole of
an artery is owing to the blood, – to a lateral distension given
by the impetus of the blood, so that the coats are expand-
ed: and the vessel, by its elasticity, the next moment reac-
quires its natural thickness. To the same impulse may
be ascribed the lateral motion of the axis, observable in
the larger arteries, if serpentine and lying in loose cellular
substance. (F)

The genuine systole, produced by a constriction of their
[Seite 65] usual thickness, scarcely occurs, probably, while the heart
acts with sufficient vigour; but when they are unusually
stimulated, or if the action of the heart fails or is impeded by
severe disease, then indeed the arteries may suppply its place
and propel the blood by their own vital energy.

131. Since Whytt* and other illustrious physiologists
have been convinced that the influence of the heart could
not reach the extreme arteries ann the origins of the veins, they
have ascribed the progression of the blood in those vessels to
a kind of oscillation, and have happily employed this to de-
monstrate the nature of inflammation. Many kinds of phe-
nomena, both physiological, as those regarding animal heat,
and pathological, as those observed in spasms, and particular-
ly in fevers, favour the supposition of this oscillatory faculty,
though it is not demonstrable to the eye.

132. It remains now to inquire into the aid given to
the returning blood by the veins, not alluding at all to
their radicles. We should conclude at first sight that
they have less active power than the rest of the san-
[Seite 66] guiferous system, and that the return of their purple blood
to the heart is chiefly ascribable to the impetus a tergo of
the arterial blood, and to their valvular structure which pre-
vents any reflux. The efficacy of the valves in this point of
view, is shown by those distensions and infractions of the
veins in the lower part of the abdomen, which are found desti-
tute of valves.*

The existence of vital powers in the venous trunks, is
probable, from the example of the liver and placenta (127),
and from experiments instituted on living animals. We for-
merly mentioned the muscular appearance in the extreme
veins near the heart (95).

133. These are the chief powers which move the blood
and depend upon the structure and vitality of the sangui-
ferous system: we say nothing of the effect of gravity, attrac-
tion, and other powers, common to all matter. The more re-
mote assistance derived after birth from peculiar functions,
v.c. respiration and muscular motion, will be manifest in our
account of those functions.



NOTES.

(A) Dr. W. Hunter first accounted for this in 1746.

‘“The systole and diastole of the heart, simply, could
not produce such an effect; nor could it have been pro-
duced, if it had thrown the blood into a straight tube, in
the direction of the axis of the left ventricle, as is the
[Seite 67] case with fish, and some other classes of animals: but by
throwing the blood into a curved tube, viz. the aorta, that
artery, at its curve, endeavours to throw itself into a
straight line, to increase its capacity; but the aorta being
the fixed point against the back, and the heart in some de-
gree loose and pendulous, the influence of its own action is
thrown upon itself, and it is tilted forwards against the inside
of the chest.”’*

Dr. Barclay has the following passage on this point.

‘“When the blood is forced into the arteries, their cur-
vatures, near where they issue from the ventricles, are
from their distension lengthened and extended towards
straight lines; and, causing the heart to participate in their
motions, compel it to describe the segment of a circle,
when the apex moving atlantad and sinistrad, is made to
strike against the left side. The same kind of motion
having also been observed by the celebrated Haller, in
distending the left or systematic auricle, it must follow, that
the stroke which is given to the side, may be the effect
of two distinct causes, either acting separately, or in
combination; but acting on a heart obliquely situated, as
ours is, in the cavity of the thorax, where the aspect of
the base is atlantad and dextrad, and that of the apex
sinistrad and sacrad. In combination, as the first of the
two, by removing the pressure, will facilitate the influx of
the venous blood into the left or systemic auricle, which
is situated dorsad; so the second, by the influx of blood
into the auricle, will contribute in its turn to facilitate the
circular motion of the heart, proceeding from the arteries.”’

[Seite 68]

It is commonly believed, that the pulse of every per-
son is quicker in the evening than in the morning, and some
have supposed an increase of quickness also at noon. Upon
these suppositions Cullen builds his explanation of the noon
and evening paroxysms of hectic fever, regarding them as
merely aggravations of natural exacerbations. The exist-
ence of the noon paroxysms is doubtful, and the evening one
cannot be so explained, if the writer of a paper in a late num-
ber of the Edinburgh Journal is correct.* His observations
show the pulse to be slower in the evening, and quicker in
the morning.

(C) The heart, however, of frogs, for instance, contracts
and relaxes alternately, for a length of time, when out of the
body and destitute of blood.

(D) The influence of this vacuum first pointed out by Dr.
Wilson, has been lately very ably displayed by Dr. Carson
of Liverpool.

The quantity of the blood, the length of its course, and
the various obstacles opposed to its progress, render it
very unlikely, that the mere propulsive power of the
heart is sufficient for the circulation. But great assist-
ance must be given by the vacuum which takes place in all
the cavities of the organ, when the contraction of the mus-
cular fibres is over. The blood is thus drawn into each
relaxed cavity, and the heart performs the double office
of a forcing and a suction pump. The rapid but quiet
motion of the blood in the veins, is thus accounted for,
which would otherwise be inexplicable. The situation
[Seite 69] of the valves of the heart is also accounted for. There
are valves between the auricles and ventricles, and at the
mouths of the two great arteries, because behind each of
these four openings is a cavity of the heart, alternately di-
lating and affording a vacuum, into which, without valves,
the blood would be drawn retrograde. At the venous
openings of the auricles no valves exist, because they do
not open from a cavity of the heart, – from a part ever ex-
periencing a vacuum, and therefore the blood cannot, when
the auricles contract, move retrograde, but will necessarily
pass forwards into the ventricles, which at that moment are
affording a vacuum. The inferior elasticity and muscu-
larity of the veins are also accounted for. If veins were
capable of contracting equally with arteries, on the di-
minution of their contents, the suction influence of the
heart would constantly reduce their cavities to a smaller ca-
pacity than is requisite for their functions. The collapse
of the veins by pressure, during the suction of the heart, is
prevented by the fresh supply of blood afforded by the
vis-a-tergo, which does exist, although it cannot be consider-
ed as of itself adequate to convey the blood back to the
right auricle. The reason appears why a tied vein is emp-
tied in the part nearest the heart; its blood is drawn for-
wards by suction. We see why a punctured vein does
not bleed, if there are other veins to convey the blood dis-
charged from the arteries. The puncture necessarily re-
moves the suction influence of the heart, and the great
cause of the progress of the blood in the vein is taken away,
while it exists in full force in the other veins of the limb.
Were it not for this circumstance, a punctured vein should
afford blood very readily. If the main vein of a limb is
wounded, the blood will flow, because it receives the whole
blood of the arteries, transmitted by the vis-a-tergo, no
[Seite 70] other veins existing into which it can be drawn when the
vacuum occurs in the right auricle: what is a parallel circum-
stance, if all the veins of a limb are tied, they swell, where-
as the ligature of one causes no tumefaction in it. These
circumstances are no proof that the vis-a-tergo is sufficient
of itself to bring back the blood, because it is certain that
such a vacuum exists, and that such must be the effects of
this vacuum upon the movement of the blood: the hemor-
rhage in the former instance, and the tumefaction in the
latter, show a certain force only in the blood, which, were
it even sufficient to bring the blood back to the heart, could
not long continue after the assistance of suction was re-
moved.

From the structure of the heart it is clear that the mere
alternate relaxation of its parietes, enlarges its cavities and
forms a vacuum. Experiment proves the same. Dr. Car-
son put the hearts of some frogs just extracted into water
blood-warm. They were thrown into violent action, and,
upon some occasions, projected a small stream of a bloody
colour though the transparent fluid. It was supposed that
a stream of the same kind continued to be projected at
every succeeding contraction; but that, after the first or
second, it ceased to be observable, in consequence of
the liquid supposed to be imbibed and projected, lo-
sing its bloody tinge and becoming transparent, or of
the same colour with the fluid in which the heart was
immersed. The organ was felt by the hand to expand du-
ring relaxation. He accounts, however, for the full dila-
tation of the heart upon another principle; upon which
it will be impossible to enter into detail before the next
section.

(E) Most Physiologists grant to the capillaries irrita-
[Seite 71] bility, tonicity, or organic contractility; but some deny
that arteries possess muscular properties. Bichat’s ob-
jections are the absence of contraction on the application
of stimuli to them; the much greater resistance of the
middle coat to a distending force, than that of muscular
parts; and lastly, the difference of the changes which it
and muscles undergo, both spontaneously and by the
action of other substances.* Berzelius has multiplied
the latter description of proofs. However this may be,
they have certainly vital powers of contraction as fully as
any parts of the body. This appears in their various de-
grees of local dilatation and contraction, under inflamma-
tion, passions of the mind, &c.: and if the capillaries alone
are allowed to possess organic contractility, it is impos-
sible to say in which point of the arterial track it be-
gan.

Dr. Parry has lately instituted a number of experiments
upon this question. After ascertaining exactly the circum-
ference of arteries in animals, he killed them, and again
measured the circumference; and after the lapse of many
hours, when life must have been perfectly extinguished,
he measured the circumference a third time. Immediately
after death, the circumference was found greatly dimin-
ished, and on the third examination, it had increased again.
The first contraction arose from the absence of the blood
which distended the vessel, and antagonized its efforts to
contraction; and this contraction was evidently muscular,
or to speak more correctly, organic contraction; because
when vitality was gone, and this kind of contraction could no
longer take place, the vessel was, on the third examination,
always found enlarged.

[Seite 72]

The forced state of distenion in arteries was proved by the
contraction, immediately occurring on making a puncture in
a portion of vessel included between two ligatures. The
capacities of arteries are thus always accommodated to the
quantity of blood, and this circumstance gives the arterial
canal such properties of a rigid tube as enable an impulse at
the mouth of the aorta to be instantly communicated through-
out the canal. And this appears the great office of the con-
tractile powers of arteries, for,

(F.) They do not incessantly dilate and contract as many
imagine. Dr. Parry, on the most careful examination, could
never discover the least dilatation in them, during the sys-
tole of the ventricle, when the pulse is felt. He very pro-
perly remarks, that the pulse is felt only when arteries are
more or less compressed; by which the motion of the blood
onwards, by the impulse of a fresh portion from the left ven-
tricle is impeded: and this effort of the fluid against the ob-
structing cause, gives the sensation called the pulse.*

SECT. VIII.
OF RESPIRATION AND ITS PRINCIPAL USE.

[Seite 73]

134. The lungs,* closely connected with the heart,
both by proximity and by relation of function, are two visce-
ra, large after birth, so light as to swim in water, and com-
posed of a spongy, and, as it were, spumous, but pretty
tenacious parenchyma.

135. They fill each cavity of the chest, are contigu-
ous to the sacs of the pleurae, to which, as well as to the
other contents of the thorax, they model and apply them-
selves. (A)

137. They, in a manner, hang from the wind-pipe
usually called the aspera arteria, which, besides its inte-
rior coat always smeared with mucus, and the subjacent
very sensible nervous coat, consists of another which is
muscular, surrounding the latter, and divided, except posteri-
orly, by an indefinite number of cartilaginous falciform
arches.

137. The aspera arteria, having entered the thorax, is
bifurcated into the two bronchiae, and these, the more
deeply they penetrate into the lobes and lobules of the
lungs, are the more and more ramified, losing both their
[Seite 74] cartilaginous rings and muscular coat, until their extreme di-
visions terminate in those cells which form the chief part of the
substance of the lungs, and alternately receive and emit the air
we breathe.

138. The shape and magnitude* of the air cells are vari-
ous. The former is generally polyedrical. The latter, in
regard to surface, is scarcely to be defined: though, indeed,
the capacity of the lungs of an adult, during a strong inspira-
tion, is about 120 cubic inches. The immense size to which
the lungs may be inflated, when the chest has been opened,
has no relation to our present subject.

139. The cells are invested and connected by the common
but delicate mucous web, – the general vinculum of the body.
The texture of each must be carefully distinguished. In
healthy and very recent lungs, I have found the cells so un-
connected, that they were distended in one insulated spot by
air cautiously inflated into a fine branch of the bronchiae,
while neither the neighbouring cells, nor the cellular mem-
brane which lies between the cells, admitted a single portion.
If air is forcibly thrown in, the air cells are ruptured and con-
founded with the cellular membrane, and both parts dis-
tended.

140. The mucous web surrounding the air cells of the
lungs is supplied with innumerable blood vessels, – divi-
sions of the pulmonary artery and four pulmonary veins,
the branches of which accompany the ramifications of
the bronchiae, and, after repeated division, form at
[Seite 75] length a most delicate and immense collection of reticulated
anastomoses. This extraordinary net-work, penetrating the
mucous web on every side, closely surrounds the air cells,
so that the prodigious quantity of blood existing in the pul-
monary vessels is separated from the contact of the air by
very fine membranes only, which Hales estimated as scarcely
1/1000 part of an inch in thickness.

141. As each ramification of the bronchiae possesses a
peculiar bunch or lobule of air cells, (139) so again each
of these possesses a peculiar system of blood vessels, the
twigs of which anastomose in the net-work with one
another, but scarcely at all with the blood-vessels of the
other lobules, as is proved by microscopic observations
on living frogs and serpents, by minute injections, and
by the phenomena of vomicae and other local diseases of
the lungs.

142. The common membrane investing the lungs is the
chief seat of a remarkable net-work of lymphatic vessels,*
which run to numerous lymphatic or conglobate glands,
carefully to be distinguished from a neighbouring order of
glands called bronchial, supplied with an excretory duct, and
of the conglomerate kind.

143. The thorax, which contains the lungs, has an osseous
and cartilaginous base, somewhat resembling a bee-hive,
throughout very firm and stable, but in every part more or
less moveable, for the purpose of respiration.§

[Seite 76]

This holds good chiefly with the six pairs of true ribs be-
low the first pair, each of which is more moveable both than
the one above, and in proportion to the greater length both of
their own bodies and of their cartilaginous appendices, which
are united by a kind of amphiarthrosis to the margin of the
sternum on each side.

144. Between the edges of the ribs lie two strata of inter-
costal muscles, differing in the direction of their fibres, but
conspiring to produce the same motion.

At the base of the thorax, the diaphragm* is subtended in
the form of an arch. It is a considerable muscle, and, in the
words of Haller, next in importance to the heart. Its utility
in the mechanical part of respiration was long since shewn,
by the excellent experiments of Galen upon living animals,
to depend chiefly on the phrenic nerve.

Its antagonists are the abdominal muscles, especially the
two oblique and the transverse.

145. The thorax, thus constituted, is, after birth, di-
[Seite 77] lated by inspiration, and subsequently reduced to a smaller
capacity by expiration.

During the former act, the thorax is enlarged laterally and
inferiorly, so that the bodies of the six ribs mentioned above
(143) are elevated and their inferior margin drawn somewhat
outwards, and the arch of the diaphragm at the same time
rather depressed and flattened.

I have never observed the inferior extremity of the ster-
num, in tranquil respiration, to be thrust forwards, as some
have asserted. (13)

146. This alternate motion of the chest continues during
health and freedom from restraint, from the hour of birth
till death. Its object is, that the lungs may be expanded
to admit the air, and contracted to expel it, in perpetual alter-
nation. This alternation occurs, in an adult at rest, about 14
times in a minute, – once to about five pulsations of the
heart.

147. For man, in common with all warm-blooded animals,
cannot long retain the inspired air, but is compelled to dis-
charge it, and take in a fresh supply of this pabulum of life,
as it always has been denominated.* Common observation
teaches that, however pure may be the air entering the lungs,
it instantly undergoes remarkable changes, by which it is con-
taminated and rendered unfit for another inspiration, unless
it is renewed.

[Seite 78]

148. It may be asked what are the changes which the
air experiences during inspiration, and which consist not
in the loss of elasticity, as was formerly supposed, but
in the decomposition of its elements.* For the atmos-
pheric air which we breathe is a singular mixture of con-
stituents, differing very much in nature from each other;
and, not to mention heterogeneous matters, such as odorous
effluvia, various exhalations, and innumerable others which
are generally present, is always impregnated with aqueous
vapour, electric and magnetic matter, and generally with
carbonic acid gas; and is itself composed of unequal parts of
two aeriform fluids, viz. 79 of azotic gas, and 21 of oxygen
gas in 100.

149. In the first place we know for certain, that at
every inspiration, (the fulness of which varies infinitely
in different men of the same age, breathing placidly,) be-
sides the quantity of azotic gas being somewhat diminish-
ed, the oxygen gas is in a great measure converted into
carbonic acid gas, or fixed air; so that the air of expira-
tion, if collected, instantly extinguishes flame and live
coals, precipitates lime from lime water, and is specifically
heavier than atmospheric air, and rendered unfit for res-
piration;§ it also contains much aqueous vapour, which
[Seite 79] is condensed in a visible form by a temperature of 60° of
Fahr.*

150. It is therefore probable, that, during inspiration,
the base of the oxygenous portion is set at liberty, and being
united with the arterial blood, is conveyed throughout the
system; while the carbon and hydrogen are brought back
with the venous blood to the right side of the heart, and
thrown off like smoke, as the ancients expressed it, in the
lungs.

The more florid colour of the arterial blood, the
darker of the venous, and the analogous appearance of
the blood, if exposed to the gases in question, (13) cor-
respond admirably with this theory. Some difficulties,
[Seite 80] indeed, remain to be solved, v.c. how the carbon can be
united in the lungs with the oxygen, so as to fly off in the
form of carbonic acid gas. (C)*

151. This perpetual change of elements, occurring in re-
spiration after birth, we shall show to be very differently ac-
complished in the foetus, viz. by means of the connection of
the gravid uterus with the placenta. But when the child is
born and capable of volition, the congestion takes place
in the aorta, from the obstruction in the umbilical arteries:
the danger of suffocation from the cessation of those changes of
the blood, in regard to oxygen and carbon, (13) hitherto pro-
duced in the uterine placenta; the novel impression of that
element into which the child, hitherto an aquatic being, is
conveyed; the cooler temperature to which it is now ex-
posed, and the many new stimuli which are now applied,
seem to induce new motions in the body, especially the dila-
tation of the chest and the first inspiration.

The lungs, being for the first time dilated by inspiration,
open a new channel to the blood, so that, being obstructed in
the umbilical arteries, it is derived to the chest.

Since the inspired air becomes hurtful and unpleasant to
the lungs by the decomposition which it experiences, we
would ascribe to the most simple corrective powers of nature
the subsequent motion, by which the poisonous mephitis, as
it be may called, is expelled and exchanged for a fresh sup-
ply. (D)

The consideration of all these circumstances, especially
if the importance of respiration to circulation, demon-
[Seite 81] strated by the well-known experiment of Hooke,* be remem-
bered, will, in my opinion, explain the celebrated problem of
Harvey better than most other attempts of physiolo-
gists (E).§



NOTES.

(A) A correct notion can scarcely be formed from this
description. The pleura is two closed sacs, one of which is
interposed between each lung and the parietes of the chest,
one portion of the sac adhering to the latter and one to
the former; but the internal surfaces of both portions are
always in contact, because, if the parietes of the thorax ex-
pand and draw with them the external portion, the lungs at
the same time expand with air, and force out the internal in
the same proportion.

[Seite 82]

(B) To Dr. Carson we are indebted for the best account
of the mechanical part of respiration.

The substance of the lungs is highly elastic, and constantly
kept in a forced state of distension after birth by the pressure
of the atmosphere. This is evident, as upon puncturing the
walls of the thorax, the lungs instantly collapse, – a circum-
stance arising from the atmospheric pressure on the one side
being counterbalanced on the other, so that their elasticity,
experiencing no opposition, becomes effective. During
inspiration, the intercostal muscles raise and draw out
the ribs, and the diaphragm descends: the enlargement
of the thoracic cavity is instantly followed of neces-
sity by the greater distension of the substance of the
lungs from the diminished resistance to the atmosphere
gravitating in the bronchiae. The diaphrahm and in-
tercostal muscle ceasing to act, the substance of the
lungs exerts its elacticity with effect, recovers its for-
mer dimensions, and drives out the additional volume
of air just admitted, and the passive diaphragm and intercos-
tal muscles follow the shrinking substance of the lungs,
offering, from their relaxation, no resistance to the atmo-
sphere pressing on the surface of the chest and abdo-
men. Thus expiration is produced. The muscular power
of the diaphragm and intercostal muscles is far greater
than the elastic power of the lungs, and therefore when
exerted overcomes it, producing inspiration: but ceas-
ing to be exerted, the elastic power gains efficiency, and
produces expiration. ‘“The contractile power of the
diaphragm (and intercostal muscles) in conformity with
the laws of muscular motion, is irregular, remitting and
sometimes altogether quiescent. The elasticity of the
lungs, on the other hand, is equal and constant. The
superior energy of the former is balanced by the perma-
[Seite 83] nency of the latter. By the advantage which the inferior
power, from the uniformity of its operations, is enabled to
take of the remissions of its more powerful antagonist,
the ground which had been lost is recovered, and the
contest prolonged; that contest in which victory declaring
on one side or the other is the instant death of the fabric.”’
p. 223. l. c.

In the common account of respiration, the elasticity of
the lungs is unnoticed, and expiration is ascribed to the
contractions of the abdominal muscles. Now in the first
place, the elasticity of the lungs is of itself sufficient for
the purpose, and in the second, there is no proof of the
necessity of these muscles in expiration. It proceeds
equally well in cases of inanition, when their contraction
would rather enlarge than diminish the abdominal cavity,
and in experiments when they are entirely removed from
animals.

The beautiful contrivance in the shape of the thorax
deserves attention: by being conical, every degree of
motion in the diaphragm produces a greater effect on the
size of the chest than could occur were it of any other
shape.

The vacuum constantly threatening in the chest, either
from the shrinking of the lungs or the contraction of the
inspiratory muscles, and I may add from the expulsion of
blood from the ventricles of the heart, will evidently be
prevented, not only by the falling of the ribs and the ascent
of the diaphragm in the former case, and ingress of ad-
ditional air into the bronchiae in the latter, but also by
the course of venous blood into the auricles; for the venous
blood being subject to the full atmospheric pressure with-
out the chest will necessarily be driven into the chest to pre-
vent a vacuum; the arterial blood is under the same cir-
[Seite 84] cumstances, but the propelling force of the ventricles pre-
vents its retrogression. The atmospheric pressure on the
blood-vessels creates a necessity for greater strength in the
ventricles, as it impedes the progress of blood from the
heart, but it thus facilitates its return. Thus the smaller
pressure on the heart acts by the intervention of the blood,
as an antagonist to its contracting fibres, dilating them when
they become relaxed.

By the tendency to a vacuum in the cavity of the thorax,
what effect the heart loses by atmospheric resistance without
the chest, is exactly compensated within, and thus on the
whole the heart neither gains nor loses by all the various
directions of atmospheric pressure.

In the foetus the case is precisely the same, although Dr.
Carson has imagined it different, and thought it necessary to
frame a little hypothesis to reconcile circumstances. The
foetal lungs, experiencing no atmospheric pressure, are con-
tracted to the utmost, and the diaphragm suffering no stimu-
lus from the will on account of uneasy sensation arising from
want of breath, is completely relaxed and forced upwards,
to remove the vacuum, and the venous blood without the
thorax must, for the same reason, be drawn forcibly into the
right auricle, preventing the vacuum which the shrunk state
of the lungs, and the discharges of blood from the left ven-
tricle tend to produce.

The cause of the first inspiration appears to be the novel
impression of cool air upon the surface, for if at any time
we are exposed to a cold wind or plunge into cold water,
the diaphragm and intercostal muscles instantly contract,
and a strong inspiration takes place. The blood rushes
into the expanded lungs, and being afterwards obstructed
when the inspiratory muscles cease to act and the elastic
lungs shrink, gives rise to an uneasy sensation, which is in-
[Seite 85] stinctively removed by another inspiration, and thus respi-
ration afterwards continues through life. The fact of respi-
ration commencing before the chord is tied, shows that
neither the conjestion in the aorta, nor the deficiency of che-
mical changes, is the cause of the first inspiration.

The elasticity of the lungs is not sufficiently great to expel
the whole of their air in expiration, whence they remain
constantly in a certain degree of distension, and the course
of the blood through them is never completely obstructed by
expiration.

(C) It is now ascertained, that no oxygen is absorbed in
respiration, but that it goes entirely to unite with the carbon
of the blood and produce carbonic acid. Mr. Ellis* con-
tends that the carbon escapes from the vessels and unites
with the oxygen externally; and my distinguished and ex-
cellent friend Dr. Prout thinks this opinion corroborated by
a fact stated by Orfila, that when phosphorus dissolved in
oil is injected into the blood-vessels, vapours of phosphorus
acid stream from the mouth and nostrils, which would hard-
ly have occurred if the acid had been formed in the vessels,
as it would probably have remained in solution in the blood
not being volatile; – the phosphorus was probably excreted
from the vessels in minute subdivision, and united with the
oxygen of the atmosphere upon coming in contact with it,
producing phosphorous acid; and the same may be ima-
gined respecting the carbonic. The quantity of carbon
discharged amounts in an adult man to 11 oz. in twenty-
four hours, according to the experiments of Messrs. Allen
[Seite 86] and Pepys.§ But the capacity of the lungs upon which such
calculations are founded, appears to me greatly overrated.

The use of the nitrogen respired is unknown. The uni-
versality of respiration or something analogous among living
beings, and all the circumstances attending its performance,
render it probable, as Dr. Prout justly remarks, that it does
something more than discharge a little superfluous carbon.
He considers galvanism as an instrument extensively used
by the vital principle, and as galvanism must be produc-
ed by the combination of carbon with oxygen, as it is in
the battery by the union of the metal and oxygen, one
great additional purpose of respiration becomes highly pro-
bable.

According to Berzelius, the colouring matter alone pro-
duces changes upon the air, and that only when mixed with
the other constituents of the blood.*

Dr. Prout and Dr. Fyfe have found the quantity of carbonic
acid gas experience uniform variations. It is diminished by
mercury, tea, substances containing alcohol, depressing pas-
sions, and fatigue, and undergoes an increase from day-break
till noon, and a decrease from noon till sun-set, remaining at
the minimum till day-break.

(D) On the subject of all this paragraph see note B.

(E) The experiment consisted in laying the lungs com-
pletely bare, and supporting life by continuing respiration ar-
tificially. Hooke varied it by pricking the surface of the
lungs, and forcing a continued stream of air through them.
The following are the words of Harvey: ‘“It would ap-
pear that the use of expiration is to purify and ventilate the
blood, by separating from it these noxious and fuliginous
vapours.”’

SECT. IX.
OF THE VOICE AND SPEECH.

[Seite 87]

152. We have described the chief use of respiration.
We shall hereafter mention how far it contributes to the con-
version of the chyle into blood, and to the support of almost
the whole class of natural functions. Its other uses are at
present to be considered.

And first, respecting the voice.* This takes place after
birth, and proceeds from the lungs, as was observed long
ago by Aristotle, who called those animals only vocal, which
breathed by means of lungs. The voice is, properly speak-
ing, a sound, formed, by means of expiration, in the larynx,
which is a most beautifully constructed organ, fixed upon the
top of the windpipe, like a capital upon a pillar.

153. The larynx is composed of various cartilages, which
being united together in the form, as it were, of a little box,
and supplied with a considerable and wonderful apparatus of
muscles,§ may be moved altogether, or separately, according
to the variations of the voice.

[Seite 88]

154. The part of the larynx most concerned in pro-
ducing the voice, is the glottis, or narrow opening of the
windpipe, having the epiglottis suspended, and, in a manner,
fixed upon it. It is clearly ascertained, that the air, expired
from the lungs, and striking properly upon the margins of the
glottis, becomes sonorous.

155. But it has been disputed what changes the glottis un-
dergoes in modulating the voice. Whether it is alternately
widened and constricted, as Galen and Dodart supposed, or
whether, according to Ferrein, the variations of voice are ef-
fected rather by the tension and relaxation of its ligaments.

The latter, consistently with his opinion, compared the
larynx to a violin; the former, more consistently with na-
ture, to a flute.*

Every thing considered, we must conclude that the glot-
tis, when sounding, experiences both kinds of changes; since
the grave and acute modulation of the voice must depend
very much upon the alterations produced in the glottis by
the ligaments, especially the inferior thyreoarytenoids, (the
vocal chords of Ferrein,) and by the corresponding modifica-
tion of the sinuses or ventricles of the larynx.

[Seite 89]

156. That every degree of motion in the glottis is direct-
ed by the numerous muscles of the larynx, is proved by the
beautiful experiment of tying or dividing the recurrent nerves,
or par vagum,* and thus weakening or destroying the voice
of the animal. (A)

157. Man and singing birds have the power of whistling.
In the latter, it is accomplished by a larynx placed at each
extremity of the wind-pipe, and divided into two portions.
The former though possessing a single and undivided larynx,
has learned, I imagine, to imitate birds, by the coarctation
of the lips.

158. Singing, which is composed of speech and a har-
monic modulation of the voice, I conceive to be peculiar to
man, and the chief prerogative of his vocal organs. Whis-
tling is connate in birds; many of them may easily be taught
to pronounce words, and instances have been known of this
even in dogs. But it is recorded, that genuine singing has
once or twice only, then indeed but indifferently and with
the utmost difficulty, been taught to parrots; while, on the
[Seite 90] other hand, scarcely a barbarous nation exists, in which sing-
ing is not common.*

159. Speech is a singular modification of the voice, ad-
justed to the formation of the sounds of letters, by the expira-
tion of air through the mouth or nostrils, and in a great mea-
sure by the assistance of the tongue, applied and struck
against the neighbouring parts, the palate and teeth in par-
ticular, and by the diversified action of the lips.

The difference between voice and speech is therefore evi-
dent. The former is produced in the larynx; the latter by
the singular mechanism of the organs above described.

Voice is common both to brutes and man, even imme-
diately after birth, nor is entirely absent in those wretched in-
fants who are born deaf. But speech follows only the cul-
ture and employment of reason, and is consequently, like it,
the privilege of man in distinction to the rest of animal na-
ture. For brutes, natural instinct is sufficient; but man,
destitute of this and other means of supporting his exis-
tence independently, enjoys the prerogative of reason and
language; and following, by their means, his social desti-
nation, is enabled to form, as it were, and manifest his ideas,
and to communicate his wants to others by the organ of
speech.

[Seite 91]

160. The mechanism* of speech and articulation is so in-
tricate, and so little understood, that even the division of let-
ters, and their distribution into classes, is attended with
much difficulty.

The division, however, of Ammann, into vowels, semi-
vowels, and consonants, is very natural:

I. He divides the vowels§ into simple, a, e, i, y, o, u, and
mixed, ä, ö, ü.

These are formed simply by the voice.

The semi-vowels and consonants are articulated by the
mechanism of speech.

II. The semi-vowels are nasal, m, n, ng, (n before g, which
is nearly related to it,) that is, the labio-nasal m; the dente-
nasal n; and the gutture-nasal ng; or oral (lingual) r, l;
that is, r with a vibration of the tongue; or l, with the tongue
less moved.

III. The consonants are distinguished into hissing (pro-
nounced in succession) h, g, ch, s, sch, f, v, ph; that is h,
[Seite 92] formed in the throat, as it were a mere aspiration; g and
ch true consonants; s, sch, produced between the teeth; f, v,
ph,
formed by the application of the lower lip to the upper
front teeth: and explosive, (which are, in a manner, at once
exploded, by an expiration, for some time suppressed or in-
terrupted,) that is, k, q, formed in the throat; d, t, about the
the teeth; p, b, near the lips; and double (compound)
x, z.

161. We must just mention certain other modifications
of the human voice, of which some, as hiccup and cough,
belong more properly to pathology than to physiology but
are very common in the most healthy persons; and others,
as weeping and laughing, appear peculiar to the human
race.

162. Many of these are so closely allied, as frequently to
be converted into each other; most also are variously mo-
dified.

In laughter there is a succession of short and abrupt ex-
pirations.*

Coughing is a quick, violent, and sonorous expiration, fol-
lowing a deep inspiration.

Sneezing, generally the consequence of an irritation of the
mucous membrane of the nostrils, is a violent and almost con-
vulsive expiration, preceded by a short and violent inspira-
tion.

Hiccup, on the contrary, is a sonorous, very short, and
[Seite 93] almost convulsive inspiration, excited by an unusual irritation
of the cardia.*

Weeping consists of deep inspirations, quickly alternating
with long and occasionally interrupted expirations.

Sighing is a long and deep inspiration, and the subsequent
expiration is sometimes accompanied by groaning.

Nearest in relation to sighing is gaping,§ which is pro-
duced by a full, slow, and long inspiration, followed by a
similar expiration, the jaws at the same time being drawn
asunder, so that the air rushes into the open fauces and the
Eustachian tubes. It occurs from the blood passing through
the lungs too slowly; v.c. when the pressure of the air is
diminished, as upon very high mountains. A peculiar fea-
ture of gaping is the propensity it excites in others to gape
likewise; arising, no doubt, from the recollection of the plea-
sure it produced.



NOTE.

(A) M. Le Gallois has ascertained that the division of
the recurrent nerves frequently proves fatal in animals,
and that its effect is to paralyse the arytenoid muscles,
thus relaxing the ligaments of the glottis, the aperture of
which is therefore diminished. This effect, however, va-
[Seite 94] ries with the kind and age of the animal. The danger di-
minishes as the animal is older; and after a certain age, lit-
tle inconvenience follows.*

The inferior ligaments of the glottis are the chief source
of the voice, for in blowing into the trachea and larynx of
an animal a slight sound only is heard, unless you approxi-
mate the arytenoid cartilages to each other, when a sound
somewhat analogous to the voice of the animal will be pro-
duced, and more acute in proportion to their approximation:
and it will be seen, at the same time, that the sound is caus-
ed chiefly by the vibrations of the inferior ligaments of the
glottis. Again, an opening below the inferior ligaments
destroys the voice, while one above it, even through the epi-
glottis, superior ligaments and arytenoid cartilages, has no
such effect. In grave tones, the whole length of the infe-
rior ligaments may be seen in a dog to vibrate; in more
acute, the posterior part only; and in very acute, merely the
arytenoid extremity, the opening of the glottis being of
course lessened in the same proportion. These circum-
stances depend upon the thyro-arytenoid muscles, which run
or. each side from the arytenoid to the thyroid cartilage and
from the lips of the glottis (and indeed also the superior liga
ments), being covered by an aponeurosis, and this by the
mucous membrane. In proportion as these contract, they
become shorter and more tense, and lessen the mouth of the
glottis; but the complete closure of the glottis at the back
part is effected by the arytenoid muscles, which connects
the two arytenoid cartilages. As all these are voluntary
[Seite 95] muscles, the division of their nerves destroys the voice.
The division of the recurrents, which supply the arytenoid
muscles, is sufficient for this purpose; but, in some instances,
a sound still remains similar to what may be produced after
death by blowing through the larynx, after approximating the
arytenoid cartilages, and must be owing to the action of the
arytenoid muscles, which are supplied not by the recurrent
but by the laryngeal nerves. As these muscles are the chief
means of contracting the posterior part of the glottis, and
producing the most acute sounds, the division of the laryn-
geal nerves destroys almost all acute sounds and renders the
voice grave.

‘“It is therefore evident that the larynx represents a reed
with two plates, the tones of which are acute in proportion
as the plates are short, and grave in proportion as they are
long. But although this analogy is just, we must not ima-
gine that there is a perfect identity. In fact, common reeds
are composed of rectangular plates fixed on one side and free
on the three others, while the vibrating plates of the larynx,
which are also nearly rectangular, are fixed on three sides,
and free on one only. Besides, the tones of common reeds
are made to ascend or descend by varying their length; but
the plates of the larynx vary only in breadth. Lastly, the
moveable plates of the reeds of musical instruments cannot,
like the ligaments of the glottis, change every moment in
thickness and elasticity.”’* The elongation and shortening
of the trachea and of the cavity between the glottis and the
lips, and the changes of the epiglottis and of the ventricles
of the larynx, must affect the voice.

SECT. X.
OF ANIMAL HEAT.

[Seite 96]

163. Man, the mammalia, and birds, are distinguished
by the natural temperature* of their bodies greatly exceed-
ing that of the medium in which they are accustomed to
exist. Man is again distinguished from these classes of ani-
mals, by possessing a much lower temperature than they; so
that in this climate it is about 96° of Fahr. while in them,
and especially in birds, it is considerably higher.

164. This natural temperature in man, is so constant,
equable, and perpetual, that, excepting slight differences
from variety of constitution, it varies but little, even in the
coldest climate and under the torrid zone. For the opi-
nion of Boerhaave, that man cannot live in a temperature
[Seite 97] exceeding his own, has been refuted since the admirable ob-
servations* of H. Ellis, the celebrated traveller and formerly
the captain of the George, by the remarkable experiments
of many excellent physiologists. This striking prerogative
of man is evinced by his being restricted to no climate, but
inhabiting every part of the earth from Hudson’s bay, where
Mercury freezes, and from Nova Zembla, to the scorching
shore of Senegal.

165. The explanation of this circumstance is equally sim-
ple and natural, and founded on the doctrine which makes
the lungs the grand receivers, or focus, and the decomposi-
tion of the oxygenized portion of the air (148) the source
or fomites of our heat.

166. For, as the oxygenous part of the inspired air is
decomposed in the air cells of the lungs, in such a way
that its base, which by its union with latent caloric was
before aëriform, now separates from this caloric, it would
appear that, by this decomposition, one portion of the ca-
loric is rendered sensible in the bronchiae, while the other
enters in a latent form into the blood, circulating in the
[Seite 98] innumerable and delicate net-works of the pulmonary ves-
sel.*

167. When the oxygenized blood thus charged with latent
heat circulates through the aortic system, it acquires carbon
in the small vessels and sets free much of the latent heat
which it had received; in this way is our animal heat princi-
pally produced.

168. Its production and regulation, however, appear much
influenced by the secretion of fluids from the blood, both
those which are liquid and destined to solidify by assimi-
lation and nutrition, and those which are permanently
elastic.

169. Since these changes are effected by the energy of the
vital powers, the great influence of these upon our tempera-
ture must be easily perceived.

[Seite 99]

170. Many arguments render it probable, that the action
of the minute vessels, and the conversion of oxygenised in-
to carbonised blood, are dependent upon the varied excite-
ment or depression of the vital principle.

For the remarkable phenomena of the stability of our
temperature,* (proved by the thermometer, and not by the
sense of touch, which may be fallacious,) – that it is scarce-
ly increased by the heat of summer, or diminished by the
cold of winter, but found sometimes even to increase on
immersion in cold water, demonstrate that the action of the
minute vessels varies according to the temperature of the
medium in which we are placed: so that, when exposed to
a low temperature (by which their tone is probably aug-
mented) more oxygen is exchanged for carbon and more
heat evolved; while in a high and debilitating temperature
this exchange is diminished, and less heat evolved.

171. The corium which covers the body and the internal
surface of the alimentary canal, eminently contributes, if we
are not much mistaken, to regulate our temperature. For
both these organs are supplied with an immense number of
blood-vessels, being analogous in this respect to the lungs,
and are so intimately connected with the lungs, by means of
sympathy,§ as in some degree to perform a part and oc-
[Seite 100] casionally the whole of some of their functions in thier
room. This is exemplified in adults labouring under nearly
total consumption, or other violent affections, of the lungs,
and nevertheless existing for a length of time, almost with-
out respiration.*

172. This opinion respecting the action of the cutaneous
vessels in exciting, moderating, or almost extinguishing
our heat, receives much support from the physiological
and pathological facts of some parts being frequently of
a higher or lower temperature than the rest of the sys-
tem.

Thus we must attribute the coldness of the dog’s nose
to the specific action of its own vessels being modified
differently from that of the rest; so on the other hand, the
burning sometimes of the cheeks and sometimes of the palms
of the hands in hectic fever, to the locally increased action
of the vessels; not to mention other phenomena of the same
description, v.c. the heat of the genitals during the venereal
oestrum, and the irresistible coldness of the feet in certain
diseases.

173. The alimentary canal is the only internal part besides
the lungs, exposed to the contact of the atmosphere. There
is scarcely occasion to prove that it is so exposed, and that
we swallow a considerable quantity of air.

The air, when swallowed, is decomposed in the stomach
and intestines, so that, during health, it soon loses its elas-
tic form: not, however, when the capillaries of the canal are
debilitated, or when it exists in too great quantity.

The extraordinary congeries of blood-vessels in the intes-
[Seite 101] tines, on their internal surface which is usually believed
equal to the external surface of the body, agrees very well
with this idea. (A)



NOTE.

(A) No phenomenon in living bodies is more remarkable
than their peculiar temperature, and no one was more diffi-
cult solution before the progress of modern chemistry.

If two different bodies are placed in a temperature, higher
or lower than their own, for a certain length of time, they
will at the end of the period, be found not of the same, but
of different temperatures. That which has the higher tempe-
rature, is said to have a smaller capacity for caloric; that
which has the lower, a greater capacity. To raise the for-
mer to a given temperature, therefore, requires less heat than
to raise the latter to the same degree.

The temperature of solids is more easily affected by a given
quantity of heat, than that of fluids, and the temperature of
fluids than that of aeriform bodies: or in other words, solids
have a smaller capacity for caloric, than fluids, and fluids
than aeriform bodies. If, therefore, a solid becomes fluid,
or a fluid aeriform, it absorbs a great quantity of heat, though
its temperature remain precisely the same. And the con-
verse holds equally good, – if an aeriform substance becomes
liquid, or a liquid solid, the heat which it before contained is
now (from the diminished capacity of the body) much more
than sufficient for the temperature which before existed, and
the temperature of the body accordingly rises.

In respiration, the dark blood of the pulmonary artery
darts with a portion of its carbon, and acquires a florid
[Seite 102] hue. This carbon unites with the oxygen of the inspired
air, and forms carbonic acid, which is expired with the other
constituent of the atmosphere, – nitrogen or azote, – which ap-
pears to have experienced no change from inspiration.

Dr. Crawford rendered it probable, by his experiments,
that the arterial blood has a larger capacity for caloric
than the venous; and common air, than carbonic acid
gas. When, therefore, the carbon of the venous blood
unites with the oxygen of the air and forms carbonic acid,
the less capacity of this than common air for caloric, must
cause an increase of temperature, but the blood having
changed from venous to arterial, has acquired a greater
capacity than before, and absorbs the heat given out by
the carbonic acid. The blood, of course, does not become
warmer, because the heat is not more than sufficient to
render its temperature equal to what it was previously;
and indeed it is not quite sufficient for this, for the arterial
blood of the pulmonary veins is generally two degrees lower
than that of the pulmonary artery.

The body in this way acquires a fund of heat, and yet the
lungs, in which it is acquired, do not experience any eleva-
tion of temperature.

The arterial blood, charged with much heat which is
not sensible, circulating through the small vessels, becomes
venous, – acquires a dark hue, and its capacity for heat is
diminished; consequently its temperature rises: the heat
which was previously latent, is, from the decrease of capa-
city, sufficient to raise its temperature, and is evolved.
In this mode, the loss of heat which occurs from the inferior
temperature in which we live, is compensated. The fresh
supply is taken in at the lungs, and brought into use in the
minute vessels.

[Seite 103]

Of late, this theory has been brought into discredit.
All experiments upon the capacities of bodies for heat, are
very delicate and hable to error; and the opinions of Craw-
ford on this point, with respect to the gases, have been de-
nied by M.M. de la Roche and Berard, and by Dr. Davy,
with respect to arterial and venous blood.*

Mr. Brodie cut of the communication between the brain
and lungs of animals, and continued respiration artificially.
The usual chemical changes continued in the lungs upon the
blood, nevertheless the temperature of the animals diminish-
ed, and even more rapidly than if the respiration had not
been continued, owing, he says, to the succession of cool air
sent into the lungs. He therefore concludes, that animal
heat depends much more upon the nervous energy than upon
the chemical changes of the blood. But Le Gallois asserts,
that under artificial respiration the temperature falls, if every
part remain uninjured.

Many circumstances favour the doctrine of Crawford.
In high temperatures we have less necessity for the evolu-
tion of heat by the chemical changes of the blood and air;
whereas, in low temperatures, as more heat is required to
sustain the natural degree of temperature, the chemical
changes are more necessary; accordingly, in very high tem-
peratures, the arterial blood remains arterial, – is as florid in
the veins as in the arteries, and the inspired air is less vitia-
ted; in low temperatures the venous blood is extremely
dark, and the inspired air more vitiated.

Dr. Crawford states, that the chemical process of respira-
tion may, in certain cases, be the means of cooling the
body. If the pulmonary exhalation is in very great
[Seite 104] abundance, it will carry off so much of the heat given out
during the change of the oxygen into carbonic acid, that
there may not be sufficient to saturate the increased capacity
of the arterial blood; this will therefore absorb heat from
the system, as it passes along, till its temperature equals that
of the other parts.*

The temperature is also regulated by the degree of per-
spiration, and the momentum of the blood, &c. In propor-
tion as more vapour transpires from the skin, will more heat
be carried off: and as the sum of the quantity and velocity
of blood in any part is greater, the temperature of that part
will be higher. Whether Crawford’s theory be correct or
not, the production of animal temperature must still be as
evidently a chemical process as changes of temperature
among inanimate bodies. But this does not prevent it from
strictly deserving the epithet vital, because it is regulated by
the vital powers of the system, although through the instru-
mentality of chemical changes. If the high temperature of
an inflamed part is owing to the increased momentum of the
blood, yet this increased momentum is produced by the vital
powers. As there is less vigour in old than in young per-
sons, and in remote parts than in those which are near the
centre of circulation, the momentum of the blood is less in
the old than the young, and in parts remote than in parts
near the heart; hence the temperature of the old falls short
of the temperature of the young, and is stated to be in all
persons lower in proportion to the distance of parts from the
centre of the circulation.

SECT. XI.
OF THE CUTANEOUS PERSPIRATION.

[Seite 105]

174. The functions of the skin, which affords a cover-
ing to the body, are so extremely various, that they cannot
all be easily described with advantage in one chapter, but
each will far more conveniently be considered under that class
of actions to which it belongs.

For, in the first place, the skin is the organ of touch, and
will be examined in this view, under the head of animal func-
tions.

It is an organ of inhalation, and in this point of view be-
longs to the absorbent system, to be spoken of among the
natural functions.

It is likewise the organ of perspiration, and on this ac-
count related in many ways to the function of respiration,
and may, we think, very properly follow it in this place.

175. The skin consists of three membranes. The Cori-
um,
internal; the cuticle, external; and the reticulum, inter-
mediate.

176. The cuticle or epidermis,* forms the external cover-
ing of the body, is separable into lamellae, and exposed
[Seite 106] to the atmosphere, the contact of which can be borne by
scarcely any other part, if you except the enamel of the teeth.
For this reason, internal cavities and the canals which com-
municate with the surface for the purpose of admitting air,
especially the respiratory passages, and the whole of the ali-
mentary canal, the tongue, the inside of the cheeks, the fau-
ces, and the organ of smell, are covered by a fine epithelium,
originating from the epidermis.*

177. The texture of the epidermis is extremely simple,
destitute of vessels, nerves, and of true mucous web, and
consequently but little organized; very peculiar, how
ever, remarkably strong, considering its pellucidity and
[Seite 107] delicacy, so that it resists for a great length of time
maceration, suppuration, and other modes of decay, and
is reproduced more easily than any other of the similar
parts.

178. It is completely sui generis, somewhat like a horny
lamella, and adheres to the subjacent corium by the interven-
tion of a mucus, and by numerous very delicate fibrils, which
penetrate the latter.*

The pores which Leuwenhoek imagined in it, do not ex-
ist; but it allows a very ready passage to caloric, carbon,
hydrogen, and to matters immediately composed of these,
v.c. oil.

179. The importance of the cuticle to organized systems,
is demonstrated by its universality in the animal and ve-
getable kingdoms; and by its being distinctly observable
in the embryo from the third month at latest after concep-
tion.

180. The inner part of the cuticle is lined by a fine
mucous membrane, denominated from the opinion of its
discoverer, reticulum Malpighianum, and by means of
which chiefly the cuticle is united more firmly to the
corium.

Its nature is mucous, it is very soluble, and, being thicker
in Ethiopians, may be completely separated in them both
[Seite 108] from the corium and cuticle, and made to appear as a true
distinct membrane.*

181. Our colour resides in it. In all persons the corium
is white, and in almost all the cuticle white and semi-pellu-
cid; in Ethiopians, indeed, alone, it inclines to grey. But
the mucous reticulum varies after birth, with age, mode of
life, and especially with difference of climate.

Thus among the four varieties into which I would divide
the human race, in the first, which may be termed Cauca-
sian, and embraces Europeans, (except the Laplanders and
the rest of the Finnish race,) the western Asiatics, and the
northern Africans, it is more or less white.

In the second, or Mongolian, including the rest of the Asi-
atics, (except the Malays of the peninsula beyond the
Ganges,) the Finnish races of the north of Europe, as the
Laplanders, &c. and the tribes of Eskimaux diffused over
the north of America, it is yellow, or resembling box
wood.

In the third, the Ethiopian, to which the remainder of the
Africans belong, it is of a tawny or jet black.

In the fourth, or American, comprehending all the Ame-
[Seite 109] ricans, excepting the Eskimaux, it is almost copper colour-
ed, of a dark orange or ferruginous hue.

In the fifth, or Malaic, in which I include the inhabitants
of all the islands in the Pacific Ocean, and of the Philippine
and Sunda, and those of the peninsula of Malaya, it is more
or less tawny, between the hue of fresh mahogany and that
of cloves or chesnuts.

All these shades of colour, as well as the other character-
istics of nations and individuals, run so insensibly into one
another, that all division and classification of them must be
more or less arbitrary.

182. The essential cause of the colour of the Malpighian
mucus, is, if we mistake not, the proportion of carbon which
is excreted together with hydrogen from the corium; and in
dark nations being very copious, is precipitated upon the
mucus and combined with it.*

183. The corium, which is covered by the reticulum and
epidermis, is a membrane, investing the whole body and de-
fining its surface; tough; very extensible; of different degrees
of thickness; every where closely united, and, as it were, in-
terwoven with the mucous tela, especially externally, but
more loosely on its internal surface, in which, excepting in
certain parts, we generally discover fat.

184. Besides nerves and absorbents, innumerable blood
[Seite 110] vessels of which we shall speak hereafter, penetrate to its
external surface, upon which they are shewn, by minute in-
jection, to form very close and delicate net works.

185. A vast number of sebaceous follicles also are dis-
persed throughout it, which diffuse over the skin an oil,*
thin, limpid, and not easily drying, altogether distinct from
the common sweat, and from that which possesses an oduor
resembling the odour of goats, and is peculiar to certain parts
only.

186. Lastly, almost every part of the corium is beset with
various kinds of hairs, chiefly short and delicate, more or
less downy, and found nearly every where but on the palpe-
brae, penis, the palms of the hand, and the soles of the feet.
In some parts, they are long and destined for peculiar
purposes; such are the capillamentum, the eye-brows, the
eye-lashes, the vibrissae, mustachios, beard, and the hair of
the arm-pits and pudenda.

187. Man is, generally speaking, less hairy than most
other mammalia. But, in this respect, nations differ. For,
not to mention those nations who to this day carefully pluck
out their beard or the hair in other parts, others appear natu-
rally destitute of hair; v.c. the Tunguses and Burats; on
the other hand, creditable travellers assert, that some inhabi-
tants of the islands in the Pacific and Indian Ocean, are re-
markably hairy.§

[Seite 111]

188. Nor is there less variety in the length, flexibility,
colour, and disposition to curl, both in each class of men
enumerated above (181), and in individuals, especially the
Caucasians; v.c. the hair of the head in the Caucasian
variety is rather dingy, or of a nut brown, inclined on one
hand to yellow, on the other to black; in the Mongolian
and American, it is black, stiffer, straight, and more sparing;
in the Malay, black, soft, curling, thick, and abundant; in
the Ethiopians, black and woolly; in individuals, especially
of the Caucasian variety, there are great differences, but
chiefly in respect to temperament, which is found intimately
and invariably connected with the colour, abundance, dispo-
sition to curl, &c. of the hair;* and there also exists a re-
markable correspondence between the colour of the hair and
of the iris.

189. The direction of the hairs is peculiar in certain parts,
v.c. spiral on the summit of the head, diverging upwards on
the pubes, on the exterior of the arm, as is commonly seen
in some anthropomorphous apes, (v.c. in the satyr and tro-
glodys,) running in two opposite directions towards the elbow,
i.e. downwards from the shoulder, upwards from the wrist;
to say nothing of the eye-lashes and eye-brows.

190. The hairs originate from the inner surface of the
corium, which abounds in fat. They adhere to it pretty
firmly, by a curious bulb, consisting of a double invo-
[Seite 112] lucrum;* the exterior vascular and oval, the interior cylin-
drical, apparently continuous with the epidermis, and sheath-
ing the elastic filaments of which the hair is composed, and
which are generally from five to ten in each.

191. The hairs are almost incorruptible, and always anoint-
ed by an oily halitus. Of all parts they appear most truly
electrical. They are very easily nourished, and even repro-
duced, unless where the skin is diseased.

192. Besides the functions ascribed to the integuments in
the former Section, must be enumerated their excretory
power, by which foreign and injurious matters are eliminated
from the mass of fluids.

This is exemplified in the miasmata of exanthematic dis-
eases, in the smell of the skin after eating garlic musk, &c.
in sweat and similar phenomena.

193. What is most worthy our attention, is the transpira-
tion of an aeriform fluid, denominated, after the very acute
philosopher who first applied himself professedly to in-
vestigate its importance, the perspirable Sanctorianum,§
and similar to what is expired from the lungs.ǁ It like-
[Seite 113] wise is composed of various proportions of carbon,* nitro-
gen, and hydrogen, precipitates lime from its solution, and
is unfit to support either flame or respiration.

194. The sweat, which seldom occurs spontaneously
during health and rest, unless in a high temperature, appears
to arise from the perspirable matter of Sanctorius being
too much increased in quantity by the excited action of
the cutaneous vessels, and from its hydrogen uniting with
the oxygen of the atmosphere and assuming the liquid form.

195. Upon the same hydrogen, variously modified by the
accession of other elements and constituents, would seem to
depend the natural and peculiar odour perceived in the per-
spiration and sweat of certain nations and individuals.

196. The quantity of matter perspired from the integu-
ments which, in a well grown adult, are equal to 15 square
feet, cannot be accurately estimated, but is probably about
two pounds in 24 hours.§ (A)

NOTES.

[Seite 114]

(A) The functions of the skin are but imperfectly known.
Besides forming a watery secretion (193, sq.)* and pro-
ducing changes similar to those which occur in the lungs
(171), it is believed by some to be an organ of absorption,
while others deny that absorption ever takes place unless
friction is employed, or the cuticle abraded. Dr. Currie’s
patient labouring under dysphagia seated in the oesphagus,
always found his thirst relieved by bathing, but never ac-
quired the least additional weight. Dr. Gerard’s diabetic
patient weighed no more after cold or warm bathing than
previously.§ Seguin found no mercurial effects from bathing
a person in a mercurial solution, provided the cuticle remain-
ed entire; they occurred, however, when the cuticle was abra-
ded.ǁ

But these are no proofs that water was not absorbed,
because the persons immersed did not lose in weight,
which they would have done if not immersed, owing to
[Seite 115] the pulmonary and cutaneous exhalation; this therefore must
have been counterbalanced by absorption somewhere, and no
shadow of proof can be urged against its occurrence by the
skin, as Dr. Kellie remarks in his excellent paper on the
functions of the skin.* Seguin too found two grains of the
mercurial salt disappear in an hour from the solution when
of the temperature of 18° Reaumur.

There is every reason to believe the occurrence of cuta-
neous absorption independently of friction or abrasion of the
cuticle. First, the existence of absorbents all over the sur-
face cannot be intended for use merely when friction is em-
ployed or the cuticle abraded. Secondly, we have many facts
which prove absorption without these circumstances, either
by the skin or lungs or both, while no reason can be given
why they should be attributed solely to the lungs. A boy
at Newmarket who had been greatly reduced before a race,
was found to have gained 30 oz. in weight during an hour,
in which time he had half a glass only of wine. Dr. Home
after being fatigued and going to bed supperless, gained 2
oz. in weight before seven in the morning. In three dia-
betic patients of Dr. Bardsley’s, the amount of the urine ex-
ceeded that of the ingesta, and the body even increased in
weight, and in one of the instances as much as 17 lbs. Dr.
Currie allows that in his patient, ‘“The egesta exceeded the
ingesta in a proportion much greater than the waste of his
body will explain.”’ Similar facts are recorded by De Haen,
Haller, &c. The same patients urine too after the daily use
of the bath, flowed more abundantly and became less pungent.

SECT. XII.
OF THE FUNCTIONS OF THE NERVOUS SYSTEM IN GENERAL.

[Seite 116]

197. We now come to the other class of functions termed
animal, (83 II.) by which the body and mind are connected.
They have obtained their name from existing in animal sys-
tems only, and from enjoying a greater range of operation
than those properly denominated vital.

198. The principal organs of these functions are the brain,
medulla spinalis, and the nerves, the greater part of which
originate from these sources.* They may be properly re-
ferred to two classes, sensorial and nervous: the former
comprehending all excepting the nerves and their immediate
origin, – all that serves more directly as the connection be-
tween the office of the nerves and the faculties of the mind.

199. Upon this division rests the beautiful observation
of the illustrious Sömmerring, respecting the correspon-
dence between the relative size of each class with the fa-
culties of the mind, – That the smaller the nerves are,
[Seite 117] compared with the sensorial class, the greater is the deve-
lopement of the mental faculties. In this sense, man has
the largest brain of all animated beings, – if its bulk be
compared with that of the nerves arising from it; but by
no means, if its weight be compared with that of the whole
body.

200. Besides the bony cranium, a threefold covering is af-
forded to the brain,* viz. the dura and pia mater, and be-
tween these two, the tunica arachnoidea.

201. The dura mater, which lines the inside of the cra-
nium, like a periosteum, forms various processes. By the
falx it divides the hemispheres of the cerebrum and cere-
bellum; by the tentorium it supports the posterior lobes of
the cerebrum, and prevents their pressure upon the subjacent
cerebellum.

In its various duplicatures it contains and supports the
venous sinuses,§ and prevents their pressure. These re-
[Seite 118] ceive the blood returning from the brain to the heart, the
proportion of which to the rest of the blood, Zinn long
ago very truly remarked, has been over-rated by physio-
logists.

202. Next to the dura mater lies the arachnoid, so named
from its thinness. Its use is not exactly known; it is desti-
tute of blood-vessels (5), and extended like the dura mater
merely over the substance of the brain, without following the
course of its furrows and prominences. (A)

203. On the contrary, the membrane called pia mater by
the ancients, closely follows the cortical substance of the
brain,* and possesses innumerable blood-vessels, which
penetrate into the latter. Hence, if a portion of this mem-
brane is detached, we find the external surface very smooth,
while the internal is viilous, and resembles the roots of
moss.

204. The cerebrum and cerebellum are composed of vari-
ous parts, differing in texture and figure, but unknown in
their uses. The most remarkable are the four ventricles,
in the two anterior and fourth of which is found the cho-
roid plexus, of whose function we are ignorant.§

[Seite 119]

205. The substance of the brain is twofold: the one called
cineritous or cortical, though not always situated exteriorly;
the other white or medullary. Between the two, Sömmer-
ring* has detected a third substance, most conspicuous in
the arbor vitae of the cerebellum, and the posterior lobes of
the cerebrum.

206. The proportion of the cineritous to the cortical sub-
stance, decreases as age advances; being greater in children,
less in adults. It is almost wholly composed of very fine
vessels, both sanguiferous and colourless, (92) of which
some few penetrate into the medullary substance:§ the latter
is composed, in addition to these vessels and a fine cellular
substance, of a pultaceous parenchyma, which, if examined
with glasses, exhibits no regular structure,ǁ and, upon chemi-
cal analysis, affords a peculiar matter, in some measure re-
sembling albumen.

207. The brain, after birth, undergoes a constant and
gentle motion,** correspondent with respiration; so that
[Seite 120] when the lungs shrink in expiration, the brain rises a little,
but when the chest expands, it again subsides.*

208. The spinal marrow is continuous with the brain,
and may be said either to spring from the brain, as from a
root, or, on the contrary, to terminate in it, and grow
into its substance. Contained in the flexible canal of
the vertebrae, it is enveloped by the same membranes as
[Seite 121] the brain: its substance was also twofold, but the medullary
is exterior to the cineritious.

209. From these two sources, – the brain and spinal mar-
row, arises the greater part of those chords, which are more
or less white and soft, chiefly composed of cellular canals
containing nervous medulla,* and distributed throughout
nearly all the the soft parts, some nerves, however, may be
more properly considered as uniting with the brain and spinal
marrow, than springing from them.

210. After the numerous experiments made by Hal-
ler and other very careful observers, we are certain,
from minute anatomical examination, that many of the
similar parts do not exhibit any true vestige of nerves;
and from surgical observations,§ and dissections of living
[Seite 122] animals,* that they do not evince the least sign of feel-
ing.

Such are the cellular substance, the epidermis, and reti-
culum mucosum, the hairs and nails.

The cartilages, bones, periosteum, and marrow.

The tendons, aponeuroses, and ligaments.

Most extended internal membranes, as the dura mater and
arachnoid; the pleura, mediastinum, and pericardium; the
peritonaeum; also the cornea, &c.

The greater part of the absorbent system, especially the
thoracic duct.

Lastly, the secundines and umbilical chord. (B)

[Seite 123]

211. The ultimate origin of most nerves from the brain
cannot be detected. A question is agitated even at the pre-
sent day, whether the nerves of each side arise from the cor-
responding or the opposite portion of the brain.* The latter
opinion is countenanced by certain pathological phenomena,
and the decussation of fibres in the medulla oblongata and
conjunction of the optic nerves.§ (C)

212. A continuation of the pia mater follows the me-
dulla of the nerves at their commencement,ǁ in such a
way, as to unite very delicately with the vascular cortex.**
But as soon as they have quitted the brain or medulla
spinalis, their structure becomes peculiar, different from
all the other similar parts. They form transverse folds
more or less oblique and angular, long since described by
P.P. Mollinelli,†† who not inaptly compared them to
[Seite 124] the rugae of earth-worms, or the rings of the aspera ar-
teria.

213. The nerves, especially those which are remarkable,
for instance, the intercostals and par vagum, are every where
distinguished by ganglia, or nodules of a compact structure
and reddish ash colour, but with whose functions we are
scarcely acquainted. I am most inclined to believe with
Zinn,* that they unite more intimately the nervous filaments
which meet in them from various directions: so that each
fibre passing out, is composed of a portion of every fibre
that has entered in.

Nearly the same holds good with respect to the plexuses,
which are produced by the union and reticulated anastomo-
ses of different nerves, and by a similar contexture of fila-
ments into which the nerves are split.

214. The ganglia and plexuses are most abundantly be-
stowed upon the spinal and intercostal or sympathetic nerve.
The latter, united by a few delicate filaments only with the
rest of the nervous system, constitutes a peculiar system,
chiefly belonging to the involuntary functions. For this
reason, Bichât, viewing it as presiding over organic life,
distinguished it from the other nerves belonging to animal
life, to use his own language.

[Seite 125]

215. The terminations of the nerves are no less concealed
from us than their origins. Excepting a few, which spread
out in the form of membranes, as the optic nerve, which be-
comes the retina; the portis mollis of the seventh pair,
which forms a zone in the spiral lamina of the cochlea; the
ultimate filaments of the rest penetrating into the viscera,
muscles, corium, &c. are so intimately blended with the sub-
stance of these parts as to elude observation.

216. The parts just described, viz. the sensorium and the
nerves originating in it and distributed throughout the body,
constitute that system which, during life, is the bond of
union between the body and the mind.

217. That the mind is closely connected with the brain, as
the material condition of mental phenomena, is demonstrated,,
to omit such arguments as the immediate connection between
the brain and the organs of sense, by our consciousness and
by the mental disturbances which ensue upon affections of
the brain. (D)

218. The singular situation and form before alluded to,
of certain parts of the brain, and likewise some patho-
logical phenomena, have induced physiologists to suppose
certain parts, in particular, the seat of the soul. Some
have fixed upon the pineal gland,* others the corpus callo-
[Seite 126] sum,* the pons varolii, the medulla oblongata, the corpora
striata, and the water of the ventricles, which washes against
the origin of some nerves. Others not contented with one
spot, have assigned particular parts of the brain for individual
faculties and propensities. (E.)

219. The energy of the whole nervous system does not
depend solely upon the brain. The spinal marrow, and
even the nerves, are possessed of their own powers, which
are sufficient to produce contractions in the muscles. These
powers are probably supported by the vascular cortex of
these parts, (212). In man, the powers proper to the nerves
are less, and those depending upon the brain greater, than in
animals, especially the cold-blooded.

220. The office of the whole nervous system is twofold.
To excite motion in other parts, especially in the voluntary
muscles, of which we shall hereafter speak at large; and to
convey impressions made upon the organs of sense to the
brain, and there to excite perception; or by means of sympa-
thies (56), to give occasion to reaction.

221. Experiment and observation put these functions of
the nervous system beyond the reach of controversy. To un-
fold the nature of these functions is difficult indeed. (F.)

222. Most opinions on this subject may be divided into
two classes. The one class regards the action of the ner-
vous system as consisting in an oscillatory motion. The
other ascribes it to the motion of a certain fluid, whose
nature is a matter of dispute; by some called animal spi-
[Seite 127] rits,* and supposed to run in vessels; by others a matter
analogous to fire, to light, a peculiar ether, oxygen, electri-
city, or magnetism.

223. Although I would by no means assent to either of
these opinions, I may be allowed to observe, that most
arguments brought by one party against the hypothesis of
the other, must necessarily be rude in proportion to the sub-
tlety of the oscillations (if such exist) of the nerves or the
nervous fluid.

224. These two hypotheses may, perhaps, be united, by
supposing a nervous fluid thrown into oscillatory vibrations
by the action of stimulants.

225. The analogy between the structure of the brain and
some secreting organs, favours the belief of the existence
of a nervous fluid. But tubes and canals are evidently no
more requisite for its conveyance, than they are requisite
in bibulous paper or any other matter employed for fil-
tering.

The opinion receives much weight from the resemblance
of the action of the nerves to the phenomena produced by
the series of a galvanic apparatus and by the common elec-
trical machine, in a living animal, or in parts not quite de-
prived of vitality. These phenomena in fact long ago indu-
ced some physiologists to compare the nervous to the elec-
tric
fluid. The singular and undeniable effects attributed
[Seite 128] to animal magnetism,* as well as other phenomena which
have given rise to the belief of a kind of sentient atmosphere
surrounding the nerves, agree very well with the same hy-
pothesis.

226. If we regard the oscillation of the nerves, not as
similar to that which occurs in tense chords, but of such a
description as may be conceived to occur in the soft pulp of
the brain, we shall find many physiological phenomena exactly
corresponding with the supposition.

It is demonstrated that hearing depends upon an oscil-
lation.

In vision also it probably occurs, although not to the ex-
tent imagined by Euler.

The penetration of Hartley in following up the con-
jectures of the Great Newton,§ has rendered it so probable,
that the action of the other senses is not very dissimilar from
this oscillatory motion, that on the same supposition he
very ingeniously explains, principally by means of the
vapour of the ventricles (called by him the denser
ether)ǁ first, the association of ideas, and again by the
assistance of this, most of the functions of the animal facul-
ties. (G)

NOTES.

[Seite 129]

(A) The Pia Mater and Tunica Arachnoides were consider-
ed as the same, till the Anatomical Society of Amsterdam
confirmed, in 1665, the doubts which were arising on the
subject, and Van Horne demonstrated both membranes dis-
tinctly to his pupils. The Dura Mater corresponds with the
fibrous membranes, the Pia Mater with the cellular, and the
Tunica Arachnoides with the serous. The latter is, in na-
ture, office, and diseases, exactly like the serous; a close
sac, affording as the peritonaeum does to the abdominal
viscera, a double covering to the brain and spinal mar-
row and the nerves before their departure through the
foramina of the Dura Mater, and lining the ventricles; in-
sulating the organs on which it lies, and affording them great
facility of movement, and liable to all the morbid affections
of serous membranes.*

(B) Although no nerves can be discovered in these parts,
and although in common they have no feeling, yet that they
have in a lower degree, what in a higher is called feeling, is
shewn by the extreme sensibility which they acquire when in-
flamed, as they nearly all frequently are.

(C) Gall and Spurzheim have shewn that the nerves and
spinal marrow do not arise from the brain, but only communi-
cate with it: for where the brain is absent, the acephalous foe-
tus equally possesses them, and neither the cerebral nerves
nor the spinal marrow are in proportion to each other, in the
various species of the animal kingdom, nor the spinal nerves
to the spinal marrow.

[Seite 130]

They have also shewn that besides the numerous commu-
nications of the whole nervous system, the two sides of the
cerebrum, cerebellum, and spinal marrow, are united by com-
missures, and that the fibres of the anterior pyramidal emi-
nences decussate each other, forming an exception to the rule
observed in every other part of the brain, of the nervous fi-
bres destined to each side of the body, running on the same
side of the brain; and they hence explain why injuries of
one side of the brain sometimes influence the same, some-
times the opposite side of the body. It is to be hoped, that
morbid dissection will ascertain the correctness of their expla-
nation.*

(D) See Sect. vi. Note A, near the end, and Sect. 44, Note
E, near the beginning.

(E) Gall and Spurzheim maintain, that the fore part of the
brain is subservient to intellect, the middle to sentiments, and
the back part to propensities, and point out particular spots in
each of their divisions for particular faculties, &c. and assert
that the size of each spot, and of the corresponding part of
the cranium, shew the strength of the faculty. I refer the En-
glish reader to Dr. Spurzheim’s well known work for full in-
formation.

It must be allowed, that their enumeration of faculties and
organs may and probably is very imperfect and incorrect, that
infinitely more remains to be done, that many of Dr. Spurz-
heim’s illustrations are objectionable, not to say ridiculous,
and that his English work is a very hasty performance.

(F) While the brain is evidently the organ of mind,
the nerves united with it, and the spinal marrow, together
with its nerves, are as evidently the instruments by which
[Seite 131] it affects, and is affected by the other parts of the body, to
which these nerves are distributed. By their instrumentali-
ty, the brain contracts the voluntary muscles, influences the
functions of every part when under the operation of the dif-
ferent passions, and receives impressions made upon the
body. The consequences of divisions of the nerves or spi-
nal marrow, fully substantiate these points.

In brainless foetuses, the circulation, secretion, &c. proceed
equally as in others which, besides spinal marrow, nerves
and ganglia, possess a brain. Vegetables absorb, assimilate,
circulate, secrete, and in many instances contract on the ap-
plication of stimuli, and yet are not known to possess nerves.
Muscles after the division of the nerves which connect them
with the brain, contract equally as before, when irritated.
In animals liable to torpor, the season of torpidity produces
its effects equally upon those muscles whose nerves have
been divided, or when the brain, &c. is destroyed.

After the removal or destruction of the brain and spinal
marrow in animals, the heart still continues to act and
the blood to circulate, provided respiration is artificially
supported.* But the involuntary functions are closely
connected with the brain and spinal marrow, for the
sudden destruction of these parts or a certain portion of
them, puts a stop to the circulation; the application of
stimuli to them excites the action of the heart and even
of the capillaries after its removal; to say nothing of the
[Seite 132] influence of the passions upon them. Nay more, the invo-
luntary functions seem as dependent upon the brain and spi-
nal marrow, as they probably are upon the ganglia and gangli-
ac nerves, for the division of the par vagum, or the destruc-
tion of that part of the brain with which it is connected,
heavily impairs the functions of the lungs and of the sto-
mach;* and although the division of the spinal marrow, or
its nerves, prevents voluntary power over the corresponding
muscles, without suspending the circulation, &c. in them,
yet this, and what are dependant upon it, – nutrition and
animal heat, are evidently impaired more, I think, than can
be accounted for by the mere deficiency of muscular action.

(G) These oscillations are purely hypothetical and indeed
improbable; were their existence proved, we should know
nothing more of the real nature of the cerebral functions, for
we should have to learn what were the peculiar properties of
the nervous system, which enabled it alone of all substances
to produce, when oscillating, the phenomena which it exhi-
bits. We might as well attempt to explain the phenomena
of motion, chemical affinity and galvanism by vitality and
mind, as the phenomena of vitality and mind by mechanics,
chemical affinity or galvanism. They are altogether distinct
principles, although there can be no question, that the laws
of mechanics, chemical affinity and galvanism, are im-
portant and indispensable in every living system, in sub-
servience to life and mind. The mind, for ought we know,
may stimulate the voluntary muscles by means of galva-
nism communicated along the nerves, but then the galvanism
is not mind, it is merely an instrument employed by the
mind.

SECT. XIII.
OF THE EXTERNAL SENSES IN GENERAL, AND OF
TOUCH IN PARTICULAR.

[Seite 133]

227. We find the other function of the nerves to consist
in communicating to the sensorium the impressions made by
external objects. This is accomplished by the external
senses, which are, as it were, the watchmen of the body, and
the informers of the mind.

The latter alone belong to our present subject. For to re-
gard, with Gorter, the stimulus which inclines us to relieve
the intestines, the sensation of hunger, and other internal
calls of nature, as so many distinct senses, is unnecessary
minuteness, as Haller long since observed.*

228. Touch merits our first attention, because it is the first
to manifest itself; its organ is most extensively spread over
the whole surface, and it is affected by most properties of
external objects.

229. For we perceive not only some qualities, as heat,
hardness, weight, &c. by the touch alone; but our knowledge
obtained by other senses, respecting some qualities, is render-
ed more accurate by the touch; such qualities are figure,
distance, &c.

230. It is less falacious than the other senses, and by cul-
ture capable of such perfection, as to supply the defects of
the others, particularly of vision.

[Seite 134]

231. The skin, whose structure we formerly examined, is
the general organ of touch.* The immediate seat is the
papillae of the corium, of various forms in different parts,
commonly resembling warts, in some places fungous,
others filamentous.§ The extremities of all the cutaneous
nerves terminate in these under the form of pulpy pe-
nicilli.

232. The hands are the principal seat of touch, properly
so called, and regarded as the sense which examines solidity.
The skin of the hands has many peculiarities. In the palms
and on each side of the joints of the fingers, it is furrowed
and free from hairs, to facilitate the closing of the hand.
The extremities of both fingers and toes are furrowed inter-
nally by very beautiful lines more or less spiral;ǁ and are
shielded externally by nails.

233. These scutiform nails are bestowed upon man
only and a few other genera of mammalia (I allude to
the quadrumana which excel in the sense of touch,)** for
[Seite 135] the purpose of resisting pressure, and thus assisting the action
of the fingers, while examining objects.

They are of a horny nature, but on the whole very similar
to the epidermis. For under them lies the reticulum, which
in negroes is black;* and under this is found the corium, ad-
hering firmly to the periosteum of the last phalanx. These
constituent parts of the nails are striated lengthwise. The
posterior edge, which, in the hands, is remarkable for a little
lunated appearance, is fixed in a furrow of the skin; and the
nails are growing constantly from this, so as to be perfectly
renewed every six months.

SECT. XIV.
OF TASTE.

[Seite 136]

234. We perceive tastes by the tongue and in some de-
gree by the other neighbouring internal cutaneous parts of
the mouth; especially by the soft palate, the fauces, the inte-
rior, of the cheeks and lips: by them, however, we taste on-
ly what is acrid and very bitter.*

235. The chief organ of taste is the tongue, agile, obse-
queous, changeable in form, and from its remarkable fleshy
nature, not unlike the heart.

236. Its integuments resemble the skin. They are an
epithelium, performing the office of cuticle; the reticulum
Malpighianum; and a papillary membrane, but little differ-
ent from the corium.

237. The integuments of the tongue differ from the
skin chiefly in these respects; – In the epithelium being
moistened not by the oily fluid of the skin, but by a mucus
[Seite 137] which proceeds from the foramen caecum of Meibomius,*
and the rest of the glandular expansion of Morgagni.
And secondly, in the conformation of the papillae, which are
commonly divided into petiolated, obtuse, and conical.
The first are very few in number and situated in a lunated
series at the root of the tongue; the others, of various mag-
nitudes, lie promiscuously upon the back of the tongue,
and chiefly upon its edges and apex, where the taste is most
acute.§

238. These papillae are furnished with extreme filaments
of the lingual branch of the fifth pair;ǁ and through them
we probably acquire the power of tasting. The ninth pair**
and the branch of the eighth, which also supplies the tongue,††
appear intended rather for the various movements of this or-
gan, in manducation, deglutition, speaking, &c.

239. For the tongue to taste properly, it must be moist,
and the substance to be tasted must be liquid, holding salts
in solution.‡‡ (A) For if either is in a dry state, we may
perceive the presence of the substances by the common sense
of touch, which the tongue possesses in great acuteness but
[Seite 138] cannot discover their sapid qualities. When the tongue
tastes very acutely, the papillae around its apex and margins
are in some degree erected.



NOTE.

(A) Certainly an infinite number of bodies are sapid,
which contain no kind of salt. Some gases and metals are
sapid; they however may possibly be united with the fluids
of the mouth, before they produce an impression.

SECT. XV.
OF SMELL.

[Seite 139]

240. While taste and smell are closely related by the
proximity of their organs, they are not less so by the analo-
gy of their stimuli, and by some other circumstances. For
this reason, they have been generally named chemical or sub-
jective senses.

By smell we perceive odorous effluvia, taken in by inspira-
tion, and principally applied to that part of Schneiderian*
membrane, which invests both sides of the septum narium
and the convexities of the turbinated bones.

241. Although the same mucous membrane lines the nos-
trils and their sinuses, its nature appears different in diffe-
rent parts.

[Seite 140]

Near the exterior openings it is more similar to the skin,
and beset with sebaceous follicles, from which arise hairs,
known by the name of vibrissae.

On the septum and the turbinated bones it is fungous, and
abounds in mucous cryptae.

In the frontal, sphenoidal, ethmoidal, and maxillary sinu-
ses, it is extremely delicate, and supplied with an infinite
number of blood-vessels, which exhale an aqueous dew.

242. It appears the principal, not to say the sole use of the
sinuses,* to supply this watery fluid, which is perhaps first
conveyed to the three meatus of the nostrils, and afterwards
to the other parts of the organ, preserving them in that con-
stant state of moisture, which is indispensable to the perfec-
tion of smell.

The sinuses are so placed, that, in every position of the
head, moisture can pass from one or other of them into the
organ of smell.

243. The principal seat of smell, – the fungous portion of
the nasal membrane, besides numerous blood vessels, remark-
able for being more liable to spontaneous hemorrhage than any
others in the body, is supplied by nerves, chiefly the first
pair, which are distributed on both sides of the septum na-
rium, and also by two branches of the fifth pair. The
[Seite 141] former appear to be the seat of smell:* the latter to serve
for the common feeling of the part, which excites sneezing,
&c.

244. The extreme filaments of the first pair do not termi-
nate in papillae, like the nerves of touch and taste, but, as it
were, deliquesce into the spongy and equal parenchyma of the
nasal membrane.

245. The organ of smell is small and very imperfect at
birth. The sinuses scarcely exist. Smell consequently takes
place but late, – as the internal nostrils are gradually evolved,
and is more acute in proportion to their size and perfection.

[Seite 142]

246. No external sense is so intimately connected with the
sensorium and internal senses, nor possesses such influence
over them, as the sense of smell.*

No other is so liable to idiosyncrasies, nor so powerful in
exciting and removing syncope.

Nor is any other capable of receiving more delicate and de-
lightful impressions; for which reason, Rosseau very aptly
called smell, the sense of imagination.

No sensations can be remembered in so lively a manner as
those which are recalled by peculiar odors.

SECT. XVI.
OF HEARING.

[Seite 143]

247. Sound, which is excited by the collision of elastic bo-
dies and propagated by the air, is perceived by the sense of
hearing,* and is first recieved by the conchiform cartilaginous
external ear, which few of our countrymen have the power
of moving. By this it is collected; then conveyed into the
meatus auditorius, which is anointed by a bitter cerumen;§
and strikes against the membrana tympani, which is placed ob-
liquely in a circular furrow of the temporal bone, and sepa-
rates the meatus from the internal ear.

248. Behind this membrane lies the middle portion of the
ear, – the cavity of the tympanum, whose fundus is directed
upwards and inwards.

It contains threeǁ ossicula auditus: of which the exterior,
[Seite 144] or malleus, adheres by its manubrium to the membrana tym-
pani, is generally united in the adult to the circular furrow
above-mentioned by its spinous process which is directed
forwards, and it lodges its round head in the hody of the
incus.

The incus is united to the head of the stapes by the extre-
mity of its long process which extends into the cavity of the
tympanum.

The stapes resting its base upon the fenestra ovalis, runs
towards the vestibule of the labyrinth, into which, sounds,
struck against the membrana tympani, are propagated by the
intervention of these three little bones.

249. The Eustachian tube* runs from the interior of the
fauces into the cavity of the tympanum: and the inferior
scala of the cochlea has the same direction; the opening of
the latter, termed fenestra rotunda, is closed by a peculiar
membrane. The true and principal use of each is not suffi-
ciently known.

250. In the deepest part of the petrous bone is placed the
internal ear,
consisting of three parts.

First, of the vestibule, placed between the other two,
into which open not only the fenestra ovalis, but the five
orifices of the semi-circular canals which lie posteriorly,
[Seite 145] and the superior scala of the cochlea, which is placed an-
teriorly.

The vestibule and semi-circular canals loosely contain
very delicate membranous bags, lately discovered by the
celebrated Scarpa. Two of these lie in the vestibule, and
three in the semicircular canals.*

251. They, as well as the cavity of the cochlea, con-
tain a very limpid fluid, bearing the name of Cotunni,
who shewed it to be absorbed by two canals, by him de-
nominated aqueducts, and by the no less illustrious
Meckel, diverticula; the one arises from the vestibule,
the other from the inferior scala of the cochlea.

252. The portio mollis of the seventh pair, together
with the portio dura, (which afterwards runs along the
Fallopian aqueduct)§ having entered the internal acoustic
opening, transmits its medullary filaments into the lower
and cribriform part of it. These filaments run to the
vestibule and semicircular canals, but especially to the
base of the cochlea, where they form a medullary zonula,
marked by beautiful plexiform striae, which pass between
the two laminae of the septum cochleae.**

253. The oscillatory tremor, which we formerly fol-
lowed as far as the fenestra ovalis (248), is propagated to
[Seite 146] the vestibule, where, by means of the water of Cotunnius
(251), it strikes the auditory nerves distributed among the
windings of the labyrinth.

254. Besides the muscles of the malleus and stapes,*
supposed to be voluntary, the chorda tympani, which
is placed between the handle of the malleus and the
longer leg of the incus, is believed to moderate the force
of sound struck against the membrana tympani, and
afterwards to be propagated along the cavity of the tym-
panum.§

SECT. XVII.
OF SIGHT.

[Seite 147]

255. The instruments of vision, – the eyes,* are two
moveable globes, fixed to the optic nerves, whose decus-
sation we formerly noticed (211), as it were to stalks, in
such a manner, that their insertion is not exactly opposite
the centre of the cornea and iris, but behind this imagi-
nary axis, rather nearer to the nose.

256. They consist of various coats, containing pellucid
humours of different degrees of density, so placed, that
the rays of light can pass from the transparent anterior
segment of the bulb to the opposite part of the fundus.

257. The external coat is called sclerotic. It is defi-
cient in the centre, and that part is filled up by the cornea,
which is transparent, lamellated, more or less convex,
and projects like the segment of a small globe from one
of larger size.

258. The interior of the sclerotica is lined by the cho-
rioid,
which abounds in blood vessels, especially verticose
veins, and is dyed on each side by a black pigment, ad-
[Seite 148] hering however but loosely to its concave surface, in the
form of mucus.*

259. The chorioid contains the internal coat – the re-
tina,
– a medullary expansion of the optic nerve, which
passes through the sclerotica and chorioid. Its struc-
ture is very beautiful.§

In the imaginary axis of the eye, between the two prin-
cipal branches of the central artery, it is perforated by
the singular foramen of Sömmerring,** which is sur-
rounded by a yellow edge.††

[Seite 149]

260. The anterior edge of the chorioid is terminated
by a cellular belt, called orbiculis ciliaris, by which it
adheres firmly to a corresponding groove in the sclerotica;
and from which two other membranes, viz. the iris and
ciliary processes, are expanded in a circular form.

261. The iris, (whose posterior surface is lined by a
brown pigment, and termed uvea) lies anteriorly to the
ciliary processes, is flat, and washed on all sides by the
aqueous humour; narrower towards the nose, broader
towards the temples. Its texture is dense and cellular,
and contains no vestige of muscular fibre. We must
regard it, with Zinn,* as a membrane sui generis, and not
as a propagation from the chorioid. The anterior surface
is differently coloured in different persons, and, during
life, counterfeits a flocculent appearance.

262. The blood-vessels of the iris run chiefly on its
anterior surface, and are continued in the foetus into the
membrana pupillaris, which begins to open in the cen-
[Seite 150] tre, at the seventh or eighth month of pregnancy, when
the eyes have acquired some degree of size; and when,
probably, the elliptic arches of its vessels begin to be
gradually retracted into the inner ring of the iris, which
ring I have never been able to perceive distinctly before that
period.

263. The other circular membrane (260) bears the
name of ligamentum or corpus ciliare; and inclining back-
wards, is distant from the iris. Its external edge is thick,*
and adheres to the ciliary circle (260): the internal is thin,
and adherent to the margin of the capsule of the lens.
The brown pigment is copiously diffused over it.

Its anterior surface, lying opposite to the uvea, is
striated. The posterior, lying upon the vitreous humour,
is beautifully separated into about 70 flocculi, remarkable
for an indescribably minute and elegant set of blood-
vessels. These flocculi are named ciliary processes, and
their use is still an object of enquiry.

264. In the bulb of the eye, whose coats we have now
described, are contained the humours, of three principal
kinds.

The posterior, and by far the larger portion of the
globe, is filled by the vitreous humour, proportionally
larger in the human subject, especially after puberty, than
in other animals, and so dispersed in innumerable drops
[Seite 151] throughout the cells of the delicate hyaloid membrane,
that this membranaceo-lymphatic body has the singular
appearance of a tremulous jelly.

265. Anteriorly it adheres to, and by means of the zona-
ciliaris
surrounds, the capsule containing the crystalline
lens,
immediately around which lies the water of Morgagni.

The lens itself is very pellucid and cellular, but so much
more dense than the vitreous humour, that it feels be-
tween the fingers like a very tenacious gluten, although
amazingly clear. Its nucleus is more dense than the ex-
terior lamellae. These may, by management, be reduced
into extremely delicate fibres, converging from the circum-
ference to the centre.*

In the adult the lens is proportionally smaller than in
quadruped mammalia also less convex, especially on its
posterior surface.

266. The remaining space of the eye is filled by the
aqueous humour, which is very limpid, and divided by
the iris into two chambers; the anterior and larger sepa-
rating the cornea and iris; and the posterior, in which the
uvea lies towards the corpus ciliare, so small, as scarcely
believed by some to exist.

267. These most valuable parts are defended from in-
juries, both by the profundity of their situation in the or-
bits, and by the valvular coverings of the eye-lids.

In the duplicature of the palpebrae lie the sebaceous
follicles
of Meibomius, thickly distributed; and their
[Seite 152] edges are fringed by a treble or quadruple series of cilia:*
the cartilaginous tarsi serve for their support and ex-
pansion, and also facilitate their motion upon the eye-
ball.

Above the eye-lids, to use the words of Cicero, the
skin is covered by the supercilia, which preserve the eyes
from the sweat flowing from the head and forehead, and
in some measure screen them from too strong a light.

268. To lubricate the eyes, to preserve their bright-
ness, and wash away foreign matters, is the office of the
tears. Their chief source is a conglomerate gland, placed
in the upper and exterior part of the orbit. It has nu-
merous but very fine excreting ducts, which are said to
discharge about two ounces of tears upon each eye during
twenty-four hours; the tears are afterwards absorbed by
the puncta lachrymalia, the function of which may, in a
certain sense, be compared to that of the lacteals in the
villous coat of the small intestines: from the puncta they
are conveyed through the snail’s horns, as they are called,
into the lachrymal sac, and thence pass into the lower
meatus of the nostrils.(A.)

269. Thus much it was necessary to premise upon the
structure of the organ of vision. We now come to the
function of the organ, – to the explanation of vision.

The rays of light falling upon the cornea at an angle
more acute than forty-eight degrees, pass through it, and,
from both its density and figure, are considerably refracted
towards the axis of the eye. On entering the aqueous
[Seite 153] humour they experience rather a less degree of refrac-
tion.

Those rays which penetrate the pupil and are received
by the lens, are still more refracted on account of the
greater density of this medium.

The less density of the vitreous humour prevents the
focus of rays from being too small, but allows it to fall
elongated upon the retina, and exhibit the image of ob-
jects, inverse indeed necessarily from the laws of light.

270. The focus which, in this mode, falls upon the
retina, is considered as acute, not absolutely but rela-
tively, on account of the different refrangibility of colours;
but the latitude arising from this aberration of the rays,
is so small, that it not only does not obscure the clearness
of vision, in any perceptible degree, but is the source of
many advantages.*

271. The celebrated question, why we behold objects
erect, while their image is painted inversely upon the
retina, may be easily answered, by considering that ob-
jects are called inverse in relation only to those which
appear erect.

Now, since the images of all objects and of our own
bodies are painted on the retina, all in their relative situa-
tion, their relative situation must correspond as exactly
as if they were viewed erect, so that the mind (to which
a sensation excited by the image and not the image itself
is communicated) is preserved from all danger of error.

[Seite 154]

272. Since many conditions are required for distinct
vision, the Creator has wonderfully ordered the functions
of these organs.

A sufficient, but, at the same time, a definite quantity
of light, not too intense for distinct vision, is provided in
two modes: – First, according to the greater or less inten-
sity of the rays, a less or greater number of them passes
to the lens: – Secondly, that portion which is superabun-
dant and injurious to vision, is absorbed.

The first is effected by the motion of the iris; the se-
cond, by the pigmentum nigrum.

273. The iris is endowed with sufficient mobility to
accommodate itself to the intensity and distance of light,
that when exposed to a strong light or to near objects, it
may expand itself and contract the pupil, but when to a
weaker light or more remote objects, it may contract
itself and dilate the pupil.* Physiologists have given dif-
ferent explanations of this motion. Some ascribe it to
the impulse of blood into its vessels; others to con-
traction of its imaginary muscular fibres. I have shewn,
in a particular treatise, that both these circumstances are
impossible, and that it is by far more probable and na-
tural to ascribe its proximate cause to the vita propria of
the iris (42); the more remote cause, as we formerly
hinted (56), is to be sought for solely in the reaction of
the sensorium.

274. The function of the dark pigment, so frequently
[Seite 155] mentioned, (258, 261, 263,) viz. to absorb the superfluous
rays, and its importance to the perfection of vision, are
demonstrated, among other ways, by the dissection of
different kinds of animals, and by the diseased condition
of Albinos, whose eyes are very tender and impatient of
light from the absence of this pigment.*

275. The focus of the refracted rays must fall exactly
on the retina, so that the point of vision be neither pro-
duced beyond it, nor so shortened as to strike on the
vitreous body.

The latter defect exists in short-sighted persons, from
the too great convexity of the cornea, or gibbosity of the
lens.

The former is the defect of long-sighted persons, in
whom there is the opposite conformation of parts.

276. Since a perfect and sound eye beholds near and
remote objects with equal distinctness, it must of neces-
sity be supplied with appropriate powers of accommo-
dation. That these internal changes of the eye are chiefly
accomplished by the pressure of the straight muscles of
the ball, I am clearly convinced, from this among other
arguments, – that in the Greenland whale, an amphibious
animal which must see in media of different densities,
nature has most accurately provided for this, in the re-
markable structure and obsequious flexibility of the
sclerotica. (B)

[Seite 156]

277. During the waking state, the eyes are perpetually,
although insensibly, agitated, and directed towards the
axes of objects, by these muscles.

For, although the whole of the retina is sensible, it
is not all equally calculated to receive the images of
objects.

In the first place, the true axis of the human* eye,
where the optic nerve enters, is proved by the well-known
experiment of Mariote, to be nearly insensbile to light.
The principal focus of the other part of the retina, and
which must be considered as the chief instrument of dis-
tinct vision, falls upon an imaginary axis of the globe,
corresponding with the axis of the cornea and the whole
eye. This, however, as Keinster observes in opposition
to Boerhaave, is not to be understood as if only one point
of an object could be seen distinctly at once, while the eye
is fixed, and that, to behold another point, the axis of the
eye must be changed; for the sensation of a complete
object is simple and complete.

278. The habit of directing the axis of the eyes rapidly
towards objects is acquired by practice. This is proved
by the example of persons who were born blind, but have
recovered their sight after puberty;§ and of children,
[Seite 157] who seldom acquire this facility of motion before the
third month.

279. To habit we must ascribe also the circumstance of
beholding an object singly, although we have two eyes.*
For infants at first see double, and the double vision
which occasionally remains after certain diseases of the
eyes, may be removed by practice and experience.

280. The combined power of the two eyes does not ex-
ceed, according to Jurin, that of each, by more than one
tenth part.

It is needless to add, what the celebrated painter,
Leonardo da Vinci, long since remarked, – that in view-
ing distant objects, it is preferable to employ but one
eye.

281. Sight can never occur, unless the angle of vision
is at least more than 34 seconds. This was proved by
the very beautiful experiments of the acute Tob. Mayer
who formerly was one of our number. And he demon-
strated the great excellence of the human sight, by shew-
ing that this still remained the limit of vision under any
light, under the splendor of the meridian sun, and the
gloom of a lantern; so that vision remains almost equally
clear, although the light be considerably diminished.

282. We may hence infer the prodigious minuteness of
the images of objects projected upon the retina,§ and
[Seite 158] nevertheless impressed so forcibly upon it, that, under
certain circumstances, their vestiges remain, after the
removal of the objects from before the eye.*



NOTES.

(A) I am not satisfied with any account which I have
hitherto seen, of the function of the eyelids, with respect
to the tears. If I am not mistaken, the tears pass over
the ball of the eye as low as the edge of the superior
tarsus, which is so applied to the ball as not ordinarily to
allow of their ready escape under it. As the lids cover
the eye during sleep and their fine inner edges meet, the
whole of the ball is at this time readily preserved moist.
But when the eyes are open, the front of the eye between
the lids would not be moistened unless the upper tarsus
occasionally descended with the fluid contained behind
it. The fluid thus brought upon the front of the eye,
trickles down by its gravity as far as the inferior tarsus,
which also occasionally ascending, raises it somewhat.
[Seite 159] Winking thus preserves the front of the eye constantly
moist during the waking state.

It may be also observed that when the tarsi approxi-
mate, as they drive before them the moisture of the front
of the eye-ball, they quite inundate the puncta lachry-
malia, by which circumstance the puncta are of course
enabled to carry off a large quantity of the secretion,
and ordinarily to prevent its overflow, which would occur
at the centre of the lower tarsus. During sleep the puncta
are not so copiously supplied, as they have only the same
share of tears as the eye in general; and there is less
occasion for it, because the removal of the stimulus of the
air and light by the closure of the eyelids, lessens the
secretion.

M. Majendie has found the matter of the tarsal or
Meibomian glands to be not sebaceous but albuminous,
and soluble in the tears; hence we discover why, during
sleep, it accumulates on the tarsi; – because its solvent,
the tears, are not sufficiently abundant to remove it.

(B) In Albino animals, whether the rabbit, pigeon,
or mouse, the sclerotic and chorioid are nearly transpa-
rent, the latter losing its blood after death, and the image
formed upon the retina may be readily seen, without re-
moving a portion of the sclerotic. From observations of
this kind M. Majendie has found that whether the eye be
presented to a neighbouring or distant object, the image
upon the retina is equally distinct, and therefore all the
explanations of this circumstance which have been hither-
to given, founded on changes which can occur only
during life, fall to the ground, whether founded on pressure
of the ball by the recti muscles, motion of the crystalline,
contraction of the crystalline or ciliary processes, &c. He
also found that the escape of a little of the aqueous or
[Seite 160] vitreous humour, or the total removal of the former or of
the cornea, impaired the distinctness of the image; the
total removal of the aqueous humour or of the crystalline
also increased the size of the image; the removal of the
humours prevented the formation of any image; an in-
crease produced in the pupil by a circular incision of the
iris produced an increase of the image.*

SECT. XVIII.
OF THE VOLUNTARY MOTIONS.

[Seite 161]

283. We have seen that the nerves perform two
offices: (220) the one of feeling, the other of moving.
The former we have already considered; we shall now
say something with respect to the latter.

284. All the motions of the body may be divided into
voluntary and involuntary.

The pulsation of the heart, and the peristaltic motion
of the intestines and other viscera, are commonly ad-
duced as instances of involuntary motion.

The action of by far the greater number of the other
muscles is voluntary.

Respiration, sneezing, the tension of the membrana
tympani, the action of the cremaster, are regarded by
some as belonging to the former class; by others, to the
latter; and by others, as of a mixed nature.

285. If this division is narrowly examined, it will be
found embarrassed by so many difficulties, that the limits
of each class cannot well be determined.

For, on the one hand, few functions can be termed
truly involuntary, especially if we consider the connection
of the imagination and passions with the will.

Again, on the other hand, there are few voluntary
motions that may not be rendered involuntary by the force
of habit, whose influence upon our animal motions is
immense.

[Seite 162]

286. Of the latter description are those muscular
motions which, although generally voluntary, take place,
under certain circumstances, without the knowledge of
the mind, or even in opposition to its endeavours.

Thus we wink involuntarily, if a friend suddenly ap-
proaches his finger to one of our eyes, though it does not
come in contact: the ring finger generally bends if we
bend the little finger.

We often unconsciously move our limbs even while
sleeping soundly.

On the contrary, some muscles which are almost al-
ways obedient to the will, occasionally cease to be so: an
instance of this exists in the difficulty which we experi-
ence in attempting to move the hand and foot of the
same side in different directions; and in all those motions,
which, although voluntary and perfectly easy if produced
separately, are found very difficult if attempted together.*

287. Among those motions which are supposed to be
perfectly involuntary, no one is free from exception, as
far as I know, excepting the spasms of the uterus during
labour.

With respect to the motion of the heart, we have the
indubitable testimony of Baynard and Cheyne, that they
saw the famous English officer, who could stop the mo-
tion of his heart and arteries at pleasure.

There is no question that the pulsation of the heart and
[Seite 163] arteries can be accelerated or retarded by the varied state
of respiration.*

The motion of the stomach is voluntary in all rumi-
nating animals, and I myself once distinctly found it
voluntary in the human subject, in an instance of rumi-
nation.

Although the motion of the iris is involuntary in most
persons, I have been credibly informed that some have
been able, by a considerable effort, to subject it to the
will and contract the pupil in a faint light.

So numerous are the motions commonly called in-
voluntary, which become voluntary in some particular in-
dividuals, especially if aided by attention and liveliness
of imagination.

Thus I have seen some able to produce at any time a
spasmodic horripilation of the skin, by representing some
unpleasant sensation to their imagination.

Others have had the power of exciting local sweat in
the hands, &c. (A)

288. This may perhaps be explained on the principle
of sensorial reaction, (56) which may be produced by
imagination, – a mental stimulus, as easily as by a corpo-
real stimulus acting upon the sensorium (52). Many
phenomena accord admirably with this explanation; v.c.
[Seite 164] the various causes of the erection of the penis, and of the
flow of saliva.

289. The voluntary motions are the distinguishing cha-
racteristics of the animal from the vegetable kingdom.
For no plant has been discovered procuring for itself
food by means of voluntary motion; nor any animal in-
capable of locomotion, or at least of procuring sustenance
by the voluntary motion of individual members.

290. In ourselves, these motions afford a striking proof
of the intimate harmony subsisting between the body and
the mind; and which is demonstrated in the rapid and
various motions of the fingers of a good performer on the
harp, and of the vocal organs whenever we speak.*



NOTE.

(A) Those muscles I conceive, are called voluntary,
which we ordinarily have the power of directly contract-
ing: those involuntary, which we have not ordinarily the
power of directly contracting. These two definitions
appear to me unexceptionable. The latter does not con-
tradict what is unquestionably true, – that we can in-
directly affect involuntary muscles, as the heart or sto-
mach, by thinking of certain objects, and thus exciting
certain emotions; nor does the former contradict another
truth, that voluntary muscles often contract without or
[Seite 165] against our will. And this leads me to remark that the
respiratory muscles deserve the epithet voluntary as much
as any in the body, for we directly contract them: we
feel an uneasy sensation in the chest from the retardation
which occurs to the blood, and we inspire to remove it;
the uneasiness being removed, our effort ceases, and ex-
piration spontaneously ensues. It is true that the uneasi-
ness is so great that we are forced to inspire, and that
respiration continues while we are asleep. But the same
is true of all voluntary muscles. If you irritate any part
of a person asleep, an effort of some kind is made to re-
move it; and if you cause strong pain or titillation in a
person awake, he will be compelled, whatever restraint
he may attempt upon himself, to make an effort to remove
it by motion of some part, as forcible as he is compelled
to remove the uneasiness in the chest by inspiration.*

SECT. XIX.
OF MUSCULAR MOTION.

[Seite 166]

291. The immediate organs of motion, by far the most
numerous in the body, are the muscles, which form the
greatest bulk among all the similar parts.

292. They abound in azote more than other animal
parts; and the absence of this principle, from the com-
bination of hydrogen and carbon, which exists during
health, entirely converts them, under a particular morbid
affection* and after death into an adipocerous substance,
resembling soap or spermacete.

293. The muscles are distinguished from other similar
parts by two characteristic features; the one derived
from their structure, the other from their singular vital
powers.

294. This fleshy structure is so constructed of moving
fibres, sui generis, and of a very faint red colour, that
every muscle may be resolved into fibrous bands, these
into bundles of fibres, and these again into very fine
fleshy fibrils.

[Seite 167]

295. Every muscle possesses a covering of cellular
membrane,* which is so interwoven with its substance, as
to surround the bands, the bundles, and even each par-
ticular fibril.

296. Every part of the muscles is amply supplied with
blood-vessels and nervous threads. The latter appear to
deliquesce into an invisible pulp, and unite intimately
with the muscular fibres: the former are so interwoven
with the fibres, that the whole muscle is red, and acquires
its own paleness (294) only by being washed.

297. Most muscles terminate in tendons, which are
fibrous parts, but so different in colour, texture, elas-
ticity, &c. as to be readily distinguished from muscles:
thus disproving the opinion of some, that the tendinous
fibres originate from the muscular. This error arose
chiefly from the circumstance of the muscles of infants
containing a greater number of fleshy fibres, in propor-
tion to the tendinous, than those of the adult.

298. The other exclusive character of muscles (293) is
the irritability of Haller,§ the notion of which, and its
[Seite 168] difference from contractility, we formerly explained (41),
but shall now prosecute farther.

299. This irritability, or muscular power, or vis insita,
is bestowed upon all muscles, but in different degrees.*

300. The highest order are the hollow muscles which
perform the vital and natural functions, and especially
the heart, (124) whose internal surface enjoys a very
lively and permanent irritability.

Next to the heart follows the intestinal canal, particu-
larly the small intestines, which, in warm-blooded animals,
contract after the heart has ceased to show signs of irri-
tability.

Next the stomach.

Then the urinary bladder, &c.

Among the other muscles, the respiratory, v.c. the
diaphragm, the intercostals, and triangularis sterni, are
remarkable for their irritability.

Then follow the remaining muscles.

Less, but still however some, exists in the arteries (128).

Also in the venous trunks contained in the thorax (95).

Still less, if it deserve the name of irritability, in the
other blood vessels. (132)

301. Haller, the great arbitrator in the doctrine of irri-
[Seite 169] tability, has ascribed it improperly (40, 5807) I think, to
some parts possessed indeed of contractility, but in which
I have never been able to detect genuine irritability.

Such are the lacteals, glands, gall bladder, uterus, the
dartos, and the penis. (A)

And others, with no less impropriety, bestow it upon
the iris, the external surface of the lungs, &c. in which
it no more exists than in the cellular membrane and
those parts which are composed of it, – the common inte-
guments, membranes of the brain, pleura, peritonaeum,
periosteum, medullary membrane, tendons, aponeuroses,
&c. or in the proper parenchyma, of the viscera, (20) of
the liver, spleen, kidnies, secundines, the brain, and the
rest of the nervous system, every one of which parts is
destitute alike of muscular fibre, and of what is peculiar
to it, – irritability.

302. As we find muscular irritability sometimes con-
founded with the contractility of the mucous web; so
on the other hand, some eminent men, particularly in
modern times, have attributed it to the nervous energy.*
Now, although we cannot deny the influence of the
nerves upon the muscles, most strikingly shewn of late (225)
by the experiments of the celebrated Galvani and others,
and although no muscular fibril, however minute, can be
[Seite 170] found absolutely destitute of nervous pulp, we are not on
this account to assert that irritability is not a power sui
generis,
as clearly different from the nervous energy as
from contractility. For parts not muscular are not irri-
table, however abundantly they may be supplied with
nerves, as the corium, the numerous nervous viscera;
and the muscular texture alone exhibits the genuine phe-
nomena of irritability. So that from the weight of these
united arguments, to omit many others, it appears more
just to assign these phenomena to the muscular fibre
alone, than to ascribe them to the nerves, which are
common to so many other parts, but do not in these
excite the faintest sign of irritability. I say nothing of
many weighty arguments derived, for instance, from the
facts, that no proportion exists between the degree of
irritability and the number of nerves in any part; that
one description of vital powers is often very energetic,
while the other is languid in the same individual, ac-
cording to national, morbid, or more especially to sexual
variety. (B)

303. The nerves exert their influence upon the muscles,
as remote or exciting causes of their action, but by no
means as the proximate or efficient, which is the inherent
irritability of the muscles.

The passions, v.c. act upon the sensorium, this upon
the nerves of the heart, so as to excite its irritability, which
produces palpitation and other anomalous motions.

The will acts upon the sensorium, this reacts upon the
nerves of the arm, which excite muscular motion, as re-
mote causes; but the proximate cause is the irritability
of the muscles themselves.

304. With this distinction of the two causes of mus-
cular motion, the result of those experiments exactly cor-
[Seite 171] respond, which have been so frequently made by dividing
or tying the nerves.* Paralysis ensued, but irritability
continued vigorous for a length of time afterwards.

There have been cases where one limb was motionless
from paralysis, but retained its sensibility, while the other
was insensible, but still capable of motion. Others have
had great pain in paralytic parts.

305. The true efficacy of the blood so copiously afforded
to muscles, (296) in promoting their action, is not clearly
ascertained.

In the Stenonian experiment,§ indeed, paralysis of the
hind legs commonly follows the application of a ligature
upon the abdominal aorta. (C)

But after all, I am confirmed in the opinion formerly
mentioned (125), that the action of what are commonly
called voluntary muscles depends less than that of the
heart, upon the afflux of blood to the moving fibres; and
on the contaray, more than it, upon the influence of the
nerves which excite their irritability.

306. Besides these inherent powers common to all mus-
cles, there are some peculiar and adventitious, arising
from figure, situation, &c. and answering their object with
perfect accuracy.

307. From this circumstance, the muscles in general
[Seite 172] are divided into hollow and sollid. The former, as we
have seen, not directly subject to the will, belong more
to the vital and natural functions, and are consequently
not to be considered at present, while we are speaking of
the voluntary muscles, which belong to the order of
animal functions.

308. Among the latter also, there is much variety. For,
not to allude to difference of size, there is great variety
in the disposition of their bands and fasciculi, and the di-
rection of their fibres, in the proportion of the fleshy to
the tendinous part, in their course, mode of insertion, &c.

309. The greatest number are long, and their fleshy
bellies terminate at each extremity in tendinous chords,
inert, and destitute of irritability, and fixed to the bones,
which they move in the manner of levers.

310. While a very few muscles are destitute of tendons,
such as the latissimus colli, an equally small number are
not inserted into bones, such are the cremaster, as we ge-
nerally find it, the azygos uvulae, most of the muscles of
the eye, &c.

311. The muscles endowed with those common (298
sq.) and peculiar (306 sq.) powers, are thus prepared to
perform their actions, which also may be divided into
common and peculiar.

312. A property common to all muscles, and the imme-
diate consequence of their irritability, is to become shorter,
more rigid, and generally unequal, and, as it were, an-
gular, during contraction.

To attempt with J. and D. Bernoulli and other mathe-
matical physicians, to reduce this diminution to a general
admeasurement, is rendered impossible, among other
causes, by the great difference between the hollow and
solid muscles in this respect, and between the solid mus-
[Seite 173] cles themselves, v.c. between straight muscles (such as
the intercostals) and sphincters.

313. The peculiar actions of muscles (311) correspond
with their peculiar powers, and consequently vary so much
as to be referrible to no general laws.

To cite one instance out of many, that action of certain
muscles is peculiar and anomalous, which seldom occurs
alone, but nearly always subsequently to, or simultaneously
with the action of some of a different order. Such is
the action of the lumbricales, when, during rapid motions
of the fingers, they follow the action of other muscles
of the metacarpus and fore arm; and of the lateral recti
muscles of the eyes, either adducens of which seldom
acts, unless simultaneously with the abducens of the other
eye.

The commonly received law, – that a muscle during its
contraction draws the more moveable point of insertion
to the more fixed, must be considered, as Winslow wisely
remarks,* perfectly relative, and subject to different limi-
tations. Thus, for example, sometimes the one point,
and sometimes the other, may be the more moveable; ac-
cordingly, as the united action of many different muscles
may render the opposite more fixed.

And, on the other hand, although the action of the
flexors is generally so much stronger than that of their
antagonists, – the extensors, that, when the bodyis at rest,
the arms, fingers, &c. are a little bent, this does not so
much depend upon the strength of the contraction of
the flexors, as upon the voluntary relaxation of the ex-
tensors, for our own relief.

[Seite 174]

314. Every muscle has moreover a peculiar mechanism,*
adapted to the individual motions for which it is intended.
Besides the determinate figure of each, many other kinds
of assistance are afforded to their peculiar motions. The
bursae mucosae, chiefly found among the muscles of the
extremities; the annular ligaments by which some are
surrounded; the fat in which most are imbedded; the
lymphatic vapour around each; and, above all, the con-
formation of the sceleton, chiefly in regard to apophyses,
condyles, and the articulations; nay, even whole bones,
v.c. the patella, the pisiform of the carpus, and the sesa-
moid bones; are destined solely to facilitate the actions
of certain muscles.

315. In this mode is compensated, or at least diminish-
ed, that inevitable loss of power, which necessarily takes
place from the conformation and stature of the whole
system, in which, from the acute angle at which some
muscles are inserted, or the proximity of their insertion
to the centre of motion, much of that power is lost, which
would have existed, if their insertion had been more re-
mote or at a more obtuse angle.

316. The human body, possessing 450 muscles, or even
more, according to sexual or individual variety, is thus
furnished with a double advantage, – with an extreme
agility of motion in particular parts and throughout the
[Seite 175] whole; and with a surprising degree of strength and en-
durance of labour. Both these are accomplished partly
by the perfection of the muscles, which, like the perfection
of ossification, takes place at manhood; and partly by
habit and practice, the former of which in affording
strength and agility to the muscles, is demonstrated in
rope-dancers, leapers, runners, wrestlers, porters, savages,
and in the examples of ancient nations.*



NOTES.

(A) Irritability is a power of contracting upon the ap-
plication of a stimulus, ceasing with life. It compre-
hends animal and organic contractility, (See Note to
Sect. vi.) and we must suppose the lacteals, vessels of
glands, gall bladder and dartos to be possessed of it: the
uterus will hereafter be shewn positively to have muscular
fibres, and their existence will be rendered probable in
the human penis.

(B) See Note F. Sect. xii.

(C) This paralysis does not show the irritability of the
muscles to be impaired; they would doubtless contract
immediately after this experiment, upon the application
of a stimulus, as readily as they do after apoplexy. The
ligatures act immediately by depriving the nerves of the
[Seite 176] power of stimulating them; for a supply of arterial blood
is necessary to the function of the nervous system,* and
the ligature of the abdominal aorta cuts this off from the
lower part of the spinal marrow, and what originate from
it, – the nerves of the hind legs. If venous blood is sent
to the brain, death ensues, and the function of any part is
destroyed by forcing venous blood into its arteries.

Another source of paralysis must ultimately arise, – the
loss of irritability from the want of circulation in the
muscle.

SECT. XX.
OF SLEEP.

[Seite 177]

317. The faculties both of feeling and motion, pos-
sessed by the nervous system whose history we have
thus pursued, are so fatigued by their exertions in the
day, that rest is necessary during the night to recruit
them by means of sleep,* – the image of death.

318. Sleep is a periodical function, by which the inter-
course of the mind and body is suspended, and whose
phenomena now to be traced, correspond very aptly with
the supposition of a nervous fluid.

319. Besides other precursors of sleep, may be enume-
rated a gradually increasing dulness of the external senses,
and a relaxation of most, especially of the long, voluntary
muscles; a congestion of venous blood about the heart,
and relief afforded by yawning to the uneasy sensation
thus produced: lastly, a curious kind of short delirium at
the moment when sleep is all but present.

320. The phenomena of sleep, therefore, amount to
this, – that the animal functions are suspended, and all the
rest proceed more slowly and inactively. For the pulse
is slower, the animal heat, caeteris paribus, diminished,
perspiration more sparing, digestion imperfect, and nearly
[Seite 178] all the excretions (except that of the semen, which is
indeed rather unusual) suppressed. (A)

321. The remote causes of sleep are evident.* To say
nothing of narcotics, it is induced by the expenditure of
the animal powers from previous fatigue or watchfulness,
also by habit, darkness, silence, rest, &c. which acquire
their somnferous powers in some measure from habit;
by mild, continued, and uniform impressions upon certain
senses, v.c. the murmur of a rivulet, or the view of a
field of standing corn agitated by the wind, a previous
meal, intense cold applied to the surface, and other modes
of deriving blood from the head, as pediluvia, clysters,
profuse hemorrhages.

322. These remote causes may induce the proximate
cause, which, upon mature consideration, I think pro-
bably consists in a diminished or impeded flow of oxyge-
nated (arterial) blood to the brain, for that fluid is of the
highest importance, during the waking state, to the
reaction of the sensorium upon the senses and voluntary
motions.

[Seite 179]

The influx of blood is diminished by its derivation from
the brain and congestion in other parts; it is impeded by
the pressure of foreign matter upon the brain, whether
from serous or purulent collections, from depression of
fractured bones, &c.

This diminution of, or impediment to, the flow of blood
to the brain, causes a deficiency of water in the ventricles
and a collapse of them, upon which that acute and deep
physiologist, David Hartley, on whom we formerly be-
stowed praise, explains the various phenomena of dreams.*
Besides other phenomena which accord with this expla-
nation, one is very remarkable which I witnessed in a
living person, and has been already noticed, – that of the
brain sinking whenever he was asleep, and swelling again
with blood the moment he awoke.

This opinion is likewise strengthened by the production
of continued watchfulness from congestion of blood in the
head.

323. The quantity of sleep depends much upon age,
constitution, temperament, &c.; generally speaking, much
[Seite 180] sleep is the attendant of weakness, (as we find it in in-
fants born prematurely and in superannuated persons,)
and the very frequent source of fatuity and torpor.

324. We awake refreshed with sleep; and this return
to life is attended by the same phenomena as the approach
of sleep, – by gaping, usually attended with stretching,
by some degree of dulness of the senses, &c.

325. The causes of waking correspond with those of
sleeping.

The proximate is the more free return of blood to the
head.

The remote are (besides the power of custom, which is
in this respect very great) various stimuli applied to the
external or internal senses, either immediately affecting
the nervous system, as the distension of the bladder, or
mediately, by the intervention of the imagination, as in
dreaming.

326. Dreams are a wandering of the imagination, which
recalls the ideas of objects formerly perceived, especially
of objects of sight, and appears to employ and interest
itself with them.

It has been disputed whether dreams are natural during
health. Some believe that they always occur during sleep,
although they may escape our memory.* Others conceive
them the consequence only of derangement in some of
the abdominal viscera. Very healthy adults have asserted
that they never dreamt.

[Seite 181]

They are generally confused and irregular, but occa-
sionally discover extraordinary marks of reason.*

The power of corporeal stimulants is very great in pro-
ducing dreams; v.c. of the semen in producing lascivious
trains of ideas, of excessive repletion in causing frightful
appearances. We have one instance of a man, in whom
any kind of dreams could be induced, if his friends, by
gently addressing him, afforded the subject matter. This,
however, appears to be a preternatural state, between
sleeping and waking; as does also the truly diseased case
of sleep-walkers, and that affection which seizes them
with what is termed magnetic ecstacy, which is, however,
of a very different nature.

Locke and others have regarded all dreams as a species
of this mixed state. (C)



NOTES.

(A) Respiration also proceeds more slowly.

(B) It is certain that the supply of arterial blood to
every part, and especially to the nervous system, is requi-
site to its functions and its life, and that in proportion to
the activity of a part is the activity of its supply of arterial
[Seite 182] blood. Analogy, therefore, renders it more than probable,
that, during the inactivity of sleep, the brain having less
occasion for arterial blood, has a less vigorous circulation
than during the waking state; and we know that whatever
diminishes the ordinary determination of blood to the brain
(321), or impairs the movement of the blood through it,*
disposes to sleep. But although this be granted, it must
be viewed not as the ordinary cause, but as a circum-
stance, or in fact a consequence, of sleep. Increase the
activity of an organ, you increase its circulation; dimi-
nish its activity, you diminish its circulation. The altera-
tion of circulation is usually not the cause, but the con-
sequence; necessary indeed to the continuance of the
altered degree of activity in the organ, but not the cause.
The degree of activity of any part, and the degree of its
[Seite 183] circulation, are exactly and unalterably correspondent. If
the circulation through a part be mechanically increased
or diminished, the sensibility and activity of the part will,
doubtless, be proportionally increased or diminished. This
example occurs in hemorrhage; frequently both are caused
simultaneously, – when diarrhea renders the surface pale
and cold, both the blood is sent more sparingly to it, and
the action of its vessels is diminished by the increased ac-
tivity of those of the intestines; in ordinary sleep, the di-
minished circulation appears the consequence, for activity
is always followed by inactivity. Stimulate a muscle, se-
parated from the body, it contracts, but it soon refuses to
do so; after a little rest, it again contracts upon the re-
moval of the stimulus. The case of the brain is analogous;
and when, after its daily activity, it falls asleep, the dimi-
nution of its circulation consequently ensues.

(C) In sleep the action of the mind is in a high degree
suspended. But the degree of suspension is extremely
various. In ordinary sleep the mind is sufficiently alert
to feel unpleasant sensations and make an effort to remove
their causes; – whether to remove the uneasiness of im-
peded circulation in the lungs by breathing, or to draw
away the hand when tickled. Imagination is often active,
and one idea associates with it another, constituting dream-
ing; but the activity of the mind is partial, and though we
are able occasionally even to reason correctly in our
dreams, we are not sufficiently ourselves to discover the
incompatibility of many circumstances which we fancy.
In a higher degree of activity, we answer questions put to
us, although often ridiculously, as our deficiency of mental
power prevents us from keeping our associations in a proper
train; and we sometimes even perform a regular series of
movements.

[Seite 184]

Between sound sleep and the waking state are innumer-
able degrees. The great feature of sleep is the deficiency
of our active powers. If we have any external sensation,
or if the imagination riots on, presenting trains of images
to our internal senses, we reflect upon them but weakly,
make great mistakes, and however well we may reason, or
whatever corporeal movement we execute, the inferiority
of our active powers is conspicuous. That active power
is not suspended, as Mr. Dugald Stewart maintains in his
theory of dreaming,* the simple fact of breathing during
deep, to say nothing of the other motions, and the acute,
though circumscribed, reasoning which occasionally occurs
in sleep, abundantly proves to the most superficial observer.

SECT. XXI.
OF FOOD AND HUNGER.

[Seite 185]

327. As sleep repairs the loss of the animal powers,
so food repairs that of the natural, and supplies fresh ele-
mentary particles in the room of those which are con-
stantly wasting.

328. We are most effectually induced to procure and
take food by various calls of nature, all tending to the
same end; on one hand, by the intolerable torment of
hunger and thirst; and on the other, by the equally pow-
erful allurements of appetite.

329. Some ascribe hunger to an uneasiness arising in
the stomach from being empty and unoccupied; others to
the mutual friction of its rugae; others not only to the
stimulus of its fluids, now secreted in abundance, – of the
saliva and gastic juice, – but to an acrimony which they
acquire when food is not taken in proper time. (A).

330. Thirst appears referrible both to a very unpleasant
dryness of the fauces, and to the particular stimulus of
acrid matters, especially of salts, taken by the mouth. It
may be, therefore, the consequence of excessive absorp-
tion in the cavity of the mouth, such as occurs when the
mother again applies her infant to the breast immediately
after it has sucked; or, as happens not uncommonly,
when venesection or purging have been ordered. Violent
passions frequently induce thirst. (B).

[Seite 186]

331. The necessity of obeying these stimuli, is more
or less urgent according to age, constitution, and espe-
cially according to habit, and nothing can therefore be
positively affirmed respecting its intensity; but thus
much is certain, that an healthy adult, in whom all the
calls of nature are felt in their usual force,* cannot ab-
stain from food a whole day without great prostration of
strength, nor scarcely beyond eight days without danger
to his life. (C).

332. Although thirst is a violent desire, drink appears
not very necessary to life and health; for many warm
blooded animals, – mice, quails, parrots, &c. do not drink
at all; and some individuals of the human species have
lived in perfect health and strength without tasting li-
quids.

333. It has been disputed whether our food, by which
we satisfy these stimuli, is derived more advantageously
and the more consistently with nature, from the animal or
vegetable kingdom.

334. Some contend that man is herbivorous, from the
shape of his teeth,§ the length of his intestines, the dif-
[Seite 187] ference between the structure of the small and large in-
testines, and from the cells of the colon. Rousseau in-
geniously urges the circumstance that woman is naturally
uniparous and provided with two breasts.* To these ar-
guments it may be added, that some men have ruminated,
– a power peculiar to herbivorous animals; that tame
vegetable feeders are easily accustomed to animal food,
whereas carnivorous animals, excepting the dog, can
very seldom be brought to feed on vegetables.

The arguments of those who, with Helvetius, regard
man as carnivorous, are derived from the conformation
of his stomach, the shortness of the coecum, &c.

335. More careful observation, however, proves that
man is not destined for either kind of food alone, but for
both. His teeth, particularly the molares, (D) and the
peculiar structure of the intestines just alluded to, (E)
hold a middle rank between the same parts in the ferae
and in herbivorous animals. The mode in which
the condyles of the lower jaw are articulated with the
[Seite 188] temporal bones, demonstrates it in the most striking man-
ner (F).

336. As the human race exists in more parts of the
globe than any other kind of animal, we should have
been but ill provided for, if we had been destined to sub-
sist on either description of food alone; whereas man now
inhabits some countries which afford either vegetable or
animal food only.

337. Man is by far the most omniverous of all animals,
capable not only of feasting on luxurious combinations
derived from each kingdom, but of subsisting with health
and vigour on nearly one kind of the most simple food.

Thus, to mention a very few instances, many at pre-
sent live on vegetables only, on the tubera of night-shade,
(potatoes) chesnuts, dates, &c. The first families of man-
kind most probably subsisted for a long period merely
on fruits, roots, corn, and pulses.*

The nomade Moors have scarcely any other food than
gum seneka.

The inhabitants of Kamtschatka and many other shores
scarcely any other than fish.

The shepherds in the province of Caraccas in South
America, on the banks of the Oronoko, and even the
Morlachs§ in Europe, live almost entirely on flesh.

Some barbarous nations devour raw animals. This
cannot be denied to have been formerly the case with the
[Seite 189] Samojedes,* the Esquimaux, and some tribes of South
America.

Other nations are no less remarkable in their drink.

The inhabitants of many intertropical islands, espe-
cially in the Pacific Ocean, can procure no sweet water,
and instead of it drink the juice of cocoa-nuts.

Others take only sea-water.

Innumerable other facts of this kind clearly prove man
to be omnivorous.



NOTES.

(A.) If hunger arise from a sense of vacuity in the
stomach, why should it be increased by the application
of cold to the surface, the deglutition of cold liquids,
&c.?

The explanation by friction of the rugae is equally un-
satisfactory; because the friction of these, if this does
really occur, cannot be greater than the friction of the
stomach against its contents after a meal, at which time
hunger does not exist.

[Seite 190]

Nor can the presence of the gastric juice explain the
matter; because, as every one knows, no mental sensation
arises in any other organ which is not excrementory from
the stimulus of it natural fluid; and I presume that this
is the stimulus alluded to, because the mechanical sti-
mulus from the bulk of the gastric juice, occurs equally
from the presence of food, which does not excite hunger.

The supposition of an acrimony generated in the gastric
fluid, &c. is, as a cause of hunger, absurd; it would be
unfit for its purposes, and would be most likely to destroy
rather than produce appetite.

Hunger has been attributed by some to a sympathy of
the stomach with a general feeling of want in the system.
But hunger is removed immediately that a due quantity
of food is swallowed, long before the general system can
have derived benefit from the meal. The circumstance
giving rise to this opinion is the continuance of hunger,
although food be taken in abundance, in cases of scirrhus
pylorus and enlarged mesenteric glands. Here, it is
urged, the hunger continues, because the body receives
no nourishment. But, in scirrhus of the pylorus, vomit-
ing soon follows the reception of food into the stomach,
and therefore this organ is reduced to the condition in
which it was previously, and the return of hunger is easily
explicable. In diseases of the mesenteric glands, there is
in fact no obstruction to the course of the chyle. Blu-
menbach always found them permeable (427), and the
continued hunger appears rather a part of the diseased
state of the chylopoietic viscera. Besides, many cases of
imperfect nutrition, from various causes, occur without
any increase of appetite.

If hunger arose from fatigue of the stomach, it should
[Seite 191] be greatest immediately after the laborious action of di-
gestion, and gradually decrease; but it on the contrary
increases.

Were irritation the cause, hunger should be greatest
when the stomach is filled with food.

On the whole, hunger may perhaps be regarded as a
sensation arising from the corrugation of the interior coat
of the stomach.

It is increased by cold drink, by cold air applied to the
surface, by acids, bitters, and astringents; – all which may
be presumed to induce contraction of the muscular fibres
of the stomach, and thus corrugate its inner coat. It is
diminished by heat and every thing which relaxes. Again,
hunger ceases immediately that the stomach is filled,
and thus all corrugation removed.

Being, on this explanation, a sensation arising from a
local state of the stomach, it will be affected not only by
whatever affects this state, but by whatever affects also the
sensibility to this state, and therefore be subject to the
common laws of sensation. Thus, the state of the stomach
remaining the same, hunger may diminish from the occur-
rence of other sensations which attract our attention more
forcibly, by passions of the mind, &c.; as is exactly the case
with all other sensations, even with those that are morbid.
Under strong attention of the mind either to pursuits of
intellect or passion, to delightful or painful sensation, all
other sensations cease to be felt, although really violent;
and frequently, from being unattended to, do not recur.
Passions, however, may affect hunger, not only by in-
creasing or diminishing the sensibility to the corrugation,
but by increasing or decreasing the Corrugation, – the
cause of the sensation.

(B.) As hunger appears to depend upon the local con-
dition of the stomach, &c. so does thirst more evidently
[Seite 192] upon that of the fauces. Every consideration renders it
probable that thirst is the sensation of the dryness of the
parts in which it is seated. Whatever produces this dry-
ness, either by diminishing the secretion of the mouth,
&c. or by carrying off the fluid when secreted, produces
thirst, and vice versa. Being a sensation, the same may-
be repeated in regard to it as was observed respecting
hunger.

(C.) Instances of fasting for a much greater length of
time may be found in authors, but these are extraordi-
nary cases.

(D.) In carnivorous animals, the incisors are very
large; and the molares generally of an irregular wedge
form, those of the lower jaw closing in those of the upper
like seissars, and being adapted for lacerating. In the
herbivorous, the surface of the molares is horizontal or
oblique, adapted for grinding.

(E.) As the food of herbivorous animals requires more
preparation before it becomes the substance of the ani-
mal, the stomach is adapted to retain it for a length of
time. The oesophagus opens nearer the right extremity
of the stomach, and the pylorus nearer the left, so that a
blind pouch is left on either side. In the carnivorous, the
reverse is the case, and the stomach cylindrical, to favour
the quick passage of the food. For the same reason, the
intestines in the latter have generally shorter and fewer
valvulae eonniventes; and, in some instances, no eoecum.

(F.) In animals which subsist on animal food, the con-
dyles of the lower jaw are locked in an elongated glenoid
cavity, and all rotatory motion is thus prevented, as motion
upwards and downwards is sufficient for the laceration of
the food. In vegetable feeders the joint is shallow, so
that a horizontal motion is allowed for grinding the
food.

SECT. XXII.
OF MASTICATION AND DEGLUTITION.

[Seite 193]

338. The lower jaw is the chief organ of mastication,
and is supplied as well as the upper with three orders of
teeth.

With incisores, generally* scalpriform for the purpose
of biting off small pieces, and not placed in the lower
jaw, as in other mammalia, more or less horizontally,
but erect – one of the distinctive characters of the hu-
man race.

With strong conical canine teeth, by which we divide
hard substances, and which in man neither project beyond
the rest, nor are placed alone, but lie closely and in re-
gular order with the others.

With molares of various sizes, adapted for grinding,
[Seite 194] and differing conspicuously from those of other mam-
malia, by possessing gibbous apices singularly obtuse.

339. The lower jaw is connected with the skull by a
singular articulation, which holds a middle rank between
arthrodia and ginglymus; and being supplied with two
cartilaginous menisci of considerable strength, affords an
easy motion in every direction.

The digaster, assisted by the geniohyoidei and mylo-
hyodei muscles, draws the lower jaw down, when we open
the mouth.

The masseters and temporal chiefly raise it again when
we bite off any thing, and are most powerfully contracted
when we break hard substances.

Its lateral motions are accomplished by the internal
and external pterygoid.

The latter can also draw it forwards.

340. Substances are retained in the mouth and moved
and brought under the action of the teeth by the buccina-
tor and the tongue, which is very flexible and changeable
in form. (235)

341. During manducation, there occurs a flow of sa-
liva,
* which is a spumous fluid, consisting of a large
portion of water united with some albumen, and hold-
ing in solution a small quantity of phosphate of lime, –
the source of the tartar of the teeth and salivary calculi.
From being constantly applied to the tongue, it is insipid,
although it contains some microcosmic salt (phosphate of
ammonia), as well as muriatic and, invariably, a small por-
tion of oxalic acid. It is antiseptic and very resolvent.(A)

[Seite 195]

342. The saliva flows from three orders of conglomerate
glands, placed laterally and interiorally with respect to
the lower jaw.

The principal are the parotids,* which pour forth the
saliva behind the middle molares of the upper jaw, through
the Stenonian ducts.

The submaxillary, through the Whartonian.§

The sublingual, – the smallest, through the numerous
Rivinian.**

343. The excretion of saliva, amounting, according to
she arbitrary statement of Nuck,†† to a pound in twelve
hours, is augmented by stimuli and mechanical pressure,
or, if the expression may be allowed, emulsion.

The latter cause, greatly favoured by the situation of the
parotids at the articulation of the jaws, occurs when we
chew hard substances, which thus become softened.

The former occurs when acrid substances are taken into
the mouth, which are thus properly diluted; or arises from
imagination, (288) as when the mouth waters during the
desire for food.

344. The mucus of the labial and buccal glands‡‡ and
of the tongue, as well as the moisture which transudes
from the soft parts of the mouth, is mixed with the saliva.

345. This mixture of fluids poured upon a substance
[Seite 196] which we are chewing, renders it not only a pultaceous
and easily swallowed bolus, but likewise prepares it for
further digestion and for assimilation.

346. The mechanism* of deglutition, although very
complicated and performed by the united powers of many
very different parts, amounts to this. The tongue being
drawn towards its root, swelling and growing rigid, re-
ceives the bolus of food upon its dorsum, which is drawn
into a hollow form. The bolus is then rolled into the
isthmus of the fauces, and caught with a curious and
rather violent effort by the infundibulum of the pharynx,
which is enlarged and in some measure drawn forward to
receive it. The three constrictores muscles of the pha-
rynx drive it into the oesophagus. These motions are all
performed in very rapid succession and require but a short
space of time.

347. Nature has provided various contrivances for open-
ing and securing this passage.

The important motion of the tongue is regulated by the
os hyoides.

The smallest particle of food is prevented from entering
the nostrils or eustachian tubes, by means of the soft
palate,§ which, as well as the uvula suspended from its
[Seite 197] arch, and whose use is not clearly understood, is extended
by muscles of its own, and closes those openings.*

The tongue protects the glottis, for the larnyx at the
moment of deglutition is drawn upwards and forwards,
and in a manner concealed under the retracted root of
the tongue and applied to the latter in such a way, that
the glottis being also constricted and protected by the
epiglottis, is most securely defended from the entrance of
foreign substances.

348. Deglutition is facilitated by the abundance of
mucus which lubricates these parts, and which is afforded
not only by the tongue (237), but by the numerous si-
nuses of the tonsils and cryptae of the pharynx.

349. The oesophagus, through which the food must pass
previously to entering the stomach, is a fleshy canal,
narrow and strong, mobile, dilatable, very sensible, and
consisting of coats resembling, except in thickness, the
coats of the other parts of the alimentary canal.

The external coat is muscular, and possesses longitu-
dinal and transverse fibres.

The middle is tendinous, lax, more and more cellular
towards each of its surfaces, by which means it is con-
nected with the two other coats.

The interior is lined, like the alimentary tube, with
an epithelium analogous to cuticle, (176) and is lubricated
by a very smooth mucus.

[Seite 198]

350. This canal receives the approaching draught or
bolus of food, contracts upon it, propels it downwards,
and, in the case of the bolus, stuffs it down, as it were,
till it passes the diaphragm and enters the stomach.



NOTE.

(A) Saliva is composed of

Water 992 . 9
A peculiar animal matter 2 . 9
Mucus 1 . 4
Alkaline Muriates 1 . 7
Lactate of Soda and animal matter 0 . 9
Pure Soda 0 . 2
–––––––
1000 . 0
–––––––

General view of the composition of animal fluids, by
J. Berzelius, M.D. Medico-Chirurgical Transactions. Vol.
III. p. 242.

SECT. XXIII.
OF DIGESTION.

[Seite 199]

351. The stomach is the organ of digestion. It exists,
what cannot be affirmed of any other viscus, in perhaps
all animals without exception; and, if the importance of
parts may be estimated in this way, evidently holds the
first rank among our organs.

352. The human stomach* resembles a very large
leathern bottle, is capable in the adult of containing three
pints and upwards of water, and has two openings.

The superior, called cardia, at which the oesophagus,
folded and opening obliquely, expands into the stomach,
is placed at the left side of its fundus.

The inferior, placed at the right and narrower part of
the stomach, and called pylorus, descends somewhat into
the cavity of the duodenum.

353. The situation of the stomach varies accordingly
as it is in a state of repletion or depletion. When empty,
it is flaccid and hangs into the cavity of the abdomen,
its greater curvature inclining downward, while the py-
lorus, being directed upwards, forms by doubling, an
angle with the duodenum.

When full, the anterior curvature is rolled forwards,
[Seite 200] so that the pylorus lies more in a line with the duodenum,
while the cardia, on the contray, is folded, as it were,
into an angle and closed.

354. The stomach is composed of four principal coats,
separated by the intervention of three others, which are
merely cellular.

The external is common to nearly all the alimentary
canal, and continuous with the omentum, as we shall pre-
sently mention.

Within this, and united to it by cellular membrane, lies
the muscular coat, very remarkable, and the seat of the
extraordinary irritability (300) of the stomach. It consists
of strata of muscular fibres,* commonly divided into
three orders, one longitudinal and two circular, (straight
and oblique) but running in so many directions that no
exact account can be given of their course.

The third is the chief membrane. It is usually termed
nervous, but improperly, as it consists of condensed mu-
cous tela, more lax on its surfaces, which are united on
the one hand with the muscular and on the other with
the internal villous coat. It is firm and strong, and may
be regarded as the basis of the stomach.

The interior, (besides the epithelium investing the
whole alimentary canal) improperly called villous, is ex-
tremely soft and in a manner spongy, porous, and folded
into innumerable rugae, so that its surface is more ex-
tensive than that of the other coats; it exhibits very small
cells, somewhat similar to those larger cells which are so
beautiful in the reticulum of ruminants.

[Seite 201]

Its internal surface is covered with mucus, probably
secreted in the muciparous crypts which are very distinct
about the pylorus.

355. The stomach is amply furnished with nerves* from
each nervous system (214), whence arises its great sen-
sibility, from which it is so readily affected by all kinds of
stimuli, whether external, as cold, or internal, as food and
its own fluids, or mental; whence also the great and sur-
prising sympathy between it and most functions of the
system; to which are referrible the influence of all pas-
sions upon the stomach, and of the healthy condition of
the stomach upon the tranquillity of the mind.

356. The abundance and utility of the blood-vessels of
the stomach are no less remarkable. Its arteries rami-
fying infinitely upon the cellular membrane and glands,
secrete the gastric juice, which would appear to stream
continually from the inner surface of the stomach.

357. The general composition of this fluid is analogous
to that of the saliva, equally antiseptic, very resolvent,
and capable of again dissolving the milk which it has
coagulated.§

358. Digestion is performed principally by it. The
[Seite 202] food, when properly chewed and subacted by the saliva,
is dissolved* by the gastric fluid, and converted into the
pultaceous chyme, so that most kinds of ingesta lose their
specific qualities and are defended from the usual che-
mical changes to which they are liable, such as putridity,
rancidity, &c. and acquire fresh properties preparatory to
chylification.

359. This important function is probably assisted by
various acccessory circumstances. Among them, some
particularly mention the peristaltic motion, which, being
constant and undulatory, agitates and subdues the pulta-
ceous mass of food.

The existence of a true peristaltic motion in the stomach
during health, is, however, not quite certain; the undu-
latory agitation of the stomach which occurs, appears in-
tended for the purpose of driving the thoroughly dis-
solved portions downwards, while those portions which
are not completely subacted are repelled from the pylorus
by the antiperistaltic motion.

360. The other assistants commonly enumerated, are
the pressure on the stomach from the alternate motion
of the abdomen, and the high temperature maintained in
the stomach by the quantity of blood in the neighbouring
viscera and blood-vessels, which at one time was sup-
posed to be of such importance, that the word coction
was synonymous with digestion.

[Seite 203]

361. To determine the time requisite for digestion, is
evidently impossible, if we consider how it must vary
according to the quality and quantity of the ingesta, the
strength of the digestive powers, and the more or less
complete previous mastication.

During health, the stomach does not transmit the di-
gestible parts of the food before they are converted into
a pulp. The difference of food must therefore evidently
cause a difference in the period necessary for digestion.*
It may, however, be stated generally, that the chyme
gradually passes the pylorus between three and six hours
after our meals. (A)

362. The pylorus is an annular limbus, consisting not,
like the other rugae of the stomach, of merely the villous,
but also of fibres derived from the nervous and muscu-
lar coats. All these united, form a canoidal opening at
the termination of the stomach, projecting into the duode-
num, as the uterus does into the vagina, and, as it were,
embraced by it.



NOTE.

(A) The digestive process does not go on equally
through the whole mass of food, but takes place chiefly
when it is in contact with the stomach, and proceeds
gradually from the superfices to the centre of the mass.
[Seite 204] As soon as a portion is reduced to a semifluid and homo-
geneous consistence, it passes into the duodenum without
waiting till the same change has pervaded the whole
mass. During digestion, the contents of the stomach
acquire an acid of a volatile nature, and on exposure to
the air, one of a more fixed kind, probably the phos-
phoric. Inquiry into the original properties of the blood,
by W. Prout, M.D. Annals of Med. and Surg. Vol. 1,
p. 142.

SECT. XXIV.
OF THE PANCREATIC JUICE.

[Seite 205]

363. The chyme, after passing the pylorus, undergoes
new and considerable changes in the duodenum,* – a
short but very remarkable portion of the intestines, before
the nutrient chyle is separated. To this end, there are
poured upon it various secreted fluids, the most important
of which are the bile and pancreatic juice.

364. Of these we shall treat separately, beginning with
the pancreatic fluid, because it is closely allied both in
nature and function to the saliva and gastric juice al-
ready mentioned.

365. Although it is with difficulty procured pure from
living and healthy animals, all observations made in re-
gard to it establish its close resemblance to the saliva.
At the present day, it would scarcely be worth while to
mention the erroneous hypothesis of F. Sylvius and his
followers, R. De Graef, F. Schuyl,§ and others, re-
specting its supposed acrimony, long since ably refuted by
the celebrated Pechlin, Swammerdam,** and Brunner,††
[Seite 206] unless they afforded a salutary admonition, how fatal the
practice of medicine may become, if not founded on
sound physiology.

366. The source of this fluid is similar to that of the
saliva. It is the pancreas,* by much the largest conglo-
merate gland in the system, excepting the breasts, and
greatly analogous to the salivary glands in every part of
its structure, even in the circumstance of its excretory
ducts, arising by extremely small radicles, and uniting and
forming one common duct, denominated, from its disco-
verer, Wirsüngian.

This duct penetrates the tunics of the duodenum, and
supplies the cavity of this intestine with a constant stilli-
cidium of pancreatic juice.

367. The execretion of this fluid is augmented by the
same causes which affect that of the saliva; viz. by pres-
sure and stimulus.

By the former it is emulged, whenever the stomach,
being in a state of repletion, is incumbent upon the pan-
creas.

By the latter, when fresh and crude chyme enters the
duodenum and the bile flows through the opening com-
mon to it and the pancreatic fluid.

368. Its use is to dissolve the chyme, especially if im-
perfectly digested in the stomach; and at all times, by
its great abundance, to assimilate the chyme more to the
nature of the fluids, and render it fitter for chylification.

SECT. XXV.
OF THE BILE.

[Seite 207]

369. The bile is secreted by the liver,* – the most
ponderous and large of all the viscera, especially in the
foetus, in which its size is inversely as the age. The
high importance of this organ is manifested, both by its
immense supply of blood-vessels, and their extraordinary
distribution, as well as by its general existence. It is not
less common to all red-blooded animals than the heart
itself.

370. The substance of the liver is peculiar, easily dis-
tinguished at first sight from that of other viscera; con-
sisting of a parenchyma well known in colour, and deli-
cate in texture, supplied with numerous nerves§ and
lymphatics (most remarkable on the surface); with bili-
[Seite 208] ferous ducts; and blood-vessels* from which the latter
originate, both very numerous and in some instances very
large, but of different descriptions, as we shall state par-
ticularly.

371. The first blood-vessel to be noticed is the vena
portarum,
whose dissimilarity from other veins, both in
its nature and course, was formerly hinted at.(97) Its
trunk is formed from the combination of most of the vis-
ceral veins belonging to the abdomen, is supported by a
cellular sheath, called the capsule of Glisson, and on
entering the liver, is divided into branches which are
subdivided more and more as they penetrate into the sub-
stance of the organ, till they become extremely minute
and spread over every part. On this account, Galen com-
pared this system to a tree whose roots were dispersed in
the abdomen and its branches fixed in the liver.

372. The other kind of blood-vessels belonging to the
liver, are branches of the hepatic artery, which arises
from the coeliac, is much inferior to the vena portae in
size and the number of its divisions, but spreads by very
minute ramifications throughout the substance of the
liver.

373. The extreme divisions of these two vessels termi-
[Seite 209] nate in true veins, which unite into large venous trunks
running to the vena cava inferior.

374. These extreme divisions are inconceivably minute,
and collected into very small glomerules,* which deceived
Malpighi into the belief that they were glandular acini,
hexagonal, hollow, and secretory.

375. From these glomerules arise the pori biliarii, very
delicate ducts, secreting the bile from the blood, and dis-
charging it from the liver through the common hepatic
duct, which is formed from their union.

376. It has been disputed whether the bile is produced
from arterial or venous blood.

Although the former opinion is countenanced by the
analogy of the other secretions which depend upon arte-
rial blood, nevertheless more accurate investigation proves
that the greater part, if not the whole, of the biliary secre-
tion, is venous.

With respect to arguments derived from analogy, the
vena portae, resembling arteries in its distribution, may
likewise bear a resemblance to them in function. Besides,
the liver is but analogous to the lungs, in which the great
pulmonary vessels are destined for the function of the
lungs, while the bronchial arteries are intended for their
nourishment; and if we are not greatly mistaken, the use
of the hepatic artery is similar. We would, however,
by no means completely deny its importance in the secre-
[Seite 210] tion of bile, but we must regard it as inconsiderable, ad-
ventitious, and not well established (A).

377. The bile flows slowly and regularly along the
hepatic duct. The greater portion runs constantly through
the ductus communis choledochus into the duodenum,
but some passes from the hepatic duct into the cystic duct,
and is received by the gall bladder, where it remains for a
short period, and acquires the name of cystic bile.*

378. The gall-bladder is an oblong sac, nearly pyri-
form, adhering to the concave surface of the liver, and
consisting of three coats.

The exterior, completely covering it, derived from the
peritonaeum.

The middle, called nervous, as in the stomach, intes-
tines, and urinary bladder, the source of its firmness and
tone.

The interior, somewhat like the inner coat of the sto-
mach, (359) containing a net work of innumerable blood-
vessels, abundant in mucous glands, and marked by
[Seite 211] rugae,* which occasionally exhibit a beautifully cancel-
lated reticulum.

379. Its cervix is conical, terminates in the cystic duct,
is tortuous, and contains a few falciform valves.

380. The bile which has passed into the gall-bladder
is retained until, from the reclined or supine posture of
the body, it flows down from it spontaneously, or is
squeezed out by the pressure of the neighbouring jeju-
num or ileum, or of the colon when distended by faeces.

The presence of stimuli in the duodenum may derive the
bile in that direction.

The great contractility of the gall-bladder, proved by
opening living animals and by pathological phenomena,
(although it has not true irritability (301) probably assists
the discharge of bile, especially when this fluid has, by
retention, become very stimulating.

381. For the cystic bile, although very analogous to
the hepatic, (377) becomes more concentrated, viscid,
and bitter, by stagnation in the gall-bladder; the cause
of which is, in all probability, the absorption of its more
watery parts by the lymphatic vessels.§

382. Our attention must now be turned to the bile
itself, – a very important fluid, respecting the nature and
[Seite 212] use of which there has been for these thirty years more
controversy than respecting any other fluid.

The cystic bile being more perfect and better calculated
for examination, will supply our observations.

383. Bile taken from a fresh adult subject, is rather
viscid, of a brownish green colour,* inodorous, and if
compared with that of brutes, scarcely bitter.

384. Its constituent parts obtained by chemical analysis,
are, besides a large proportion of water, albumen, resin,
soda, united partly with phosphoric, sulphurous, and
muriatic acid, a small portion of phosphate of lime and
iron, and a variable quantity of a remarkable and peculiar
yellow matter.

385. The composition of the bile varies greatly both
from the proportion of its parts, particularly of the albu-
minous and resinous, differing under different circum-
stances, and also from the addition, during morbid states,
to the biliary secretion, of other constituents, especially of
adipocerous substances, which give origin to most biliary
calculi; for these consist either of it alone, or of it com-
bined with the yellow substance just mentioned (B).

386. The nature of the bile is not saponaceous and
capable of effecting a combination between water and
oils, as Boerhaave supposed, but which opinion the excel-
lent experiments of Schröder,§ who was formerly of this
[Seite 213] university, both confirmed and extended by other physio-
logists,* have disproved. It even decomposes a combi-
nation of those substances.

387. The important and various use of the bile in chyli-
fication is self-evident.

In the first place, it gradually precipitates the faeces, and
separates the milky chyle from the mixed and equable pul-
taceous chyme, while this is passing through the tract of the
small intestines, after being propelled from the stomach
into the duodenum and diluted by the pancreatic juice.

It separates itself into two portions, the one serous, the
other resinous. The latter combines with the faeces, tinges
them, and is discharged with them; the former is probably
mixed with the chyle and carried back to the blood. (C)

The bile seems to act as a stimulus to the peristaltic
motion§ of the intestines.

We shall omit other less probable uses assigned to tho
bile, viz. of exciting hunger by regurgitating into the
stomach, – a circumstance which I think can scarcely
happen during health.

NOTES.

[Seite 214]

(A) Two instances have occurred in London, of the
vena portae running not to the liver, but immediately to
the vena cava inferior. The bile must have been secreted
entirely from the blood of the hepatic artery. One of
these is described by Mr. Abernethy,* and the other is
mentioned by Mr. Lawrence.

(B) Berzelius states, that bile contains alkali and salts
in the same proportion as the blood; that no resin exists
in it, but ‘“a peculiar matter, of a bitter and afterwards
somewhat sweet taste, which possesses characters in com-
mon with the fibrin, the colouring matter, and the albu-
men of the blood.”’ This forms with an excess of acid, a
perfectly resinous precipitate. What has been considered
as albumen in the bile, Berzelius regards as the mucus of
the gall-bladder.

Bile contains of

Water 907.4
Biliary matter 80.0
Mucus of the gall bladder
dissolved in the bile

3.0
Alkalies and salts common
to all secreted fluids

9.6
–––––––
1000.0§
–––––––
[Seite 215]

(C.) During the precipitation of the chyle and the de-
composition of the bile, a gaseous product is usually
evolved, and the mass becomes neutral, and traces of an
albuminous principle
commence, strongest at a certain
distance from the pylorus, and gradually fainter in each
direction. On mixing bile with chyme out of the body,
a precipitation takes place, and the mixture becomes
neutral; but the formation of an albuminous principle is
doubtful, probably from the want of the pancreatic
fluid.*

It is wonderful that in jaundice, when no bile is seen in
the faeces, and Fordyce says even in artificial obstruction
of the choledochus by ligature, nutrition continues. Life
and health are said to continue after the removal of the
organ next to be considered, – the spleen. We know
little of the compensating resources of nature.

SECT. XXVI.
OF THE FUNCTION OF THE SPLEEN.

[Seite 216]

388. The Spleen* lies to the left side of the liver, and
with it has considerable vascular communications; its
figure is oblong; it applies itself to the contiguous visce-
ra, and is liable to great varieties in point of form, num-
ber, &c.

389. Its colour is livid, its texture singular, soft, easily
lacerated, and therefore surrounded by two membranes,
the interior of which is proper to the spleen, and the ex-
terior derived from the omentum.

390. The situation and size of the spleen are no less
various than its figure, and depend upon the degree of
repletion of the stomach: for when the stomach is empty
and lax, the spleen is turgid; when the stomach is full,
the spleen being compressed is emptied.

It undergoes a continual but gentle and equable motion,
dependent upon respiration, under the chief instrument of
which – the diaphragm, it is immediately situated.

[Seite 217]

391. Its texture was formerly supposed to be cellular,
and compared to the corpora cavernosa of the penis. This
opinion was proved to be erroneous by more careful ex-
amination of the human spleen,* which consists entirely
of blood-vessels, of enormous size in comparison with the
bulk of the organ. They are in fact proportionably more
considerable than in any other part of the body.

392. The experiments of Wintringham demonstrate
the great tenuity and strength of the coats of the splenic
artery. It is divided into an infinite number of twigs,
the terminations of which resemble pulpy penicilli and
give rise to the splenic veins, which gradually unite into
large, loose, and easily dilatable trunks.

393. This immense congeries of blood-vessels is con-
nected and supported by a sparing cellular parenchyma,
from which the adsorbents arise. The trunks of these run
along the lower surface of the spleen between the two
coasts just described.

394. This loose structure of the spleen, easily becoming
distended with blood, admirably confirms what we for-
merly remarked respecting the turgor of this organ, (390).
The congestion and slow return of the splenic blood, if
the nature of the neighbouring organs is also taken into
consideration, illustrates its peculiar properties, which
may throw some light upon the function of this enigma-
tical viscus, – the source of so much controversy.

[Seite 218]

395. The splenic blood is very fluid, coagulates with
great difficulty, separates the serum from the crassamen-
tum imperfectly, and is of a livid dark colour, like the
blood of the foetus. These circumstances clearly demon-
strate the abundance in it of carbonaceous matter; which
is likewise proved indisputably by an easy experiment.
Whenever we have exposed sections of a recent spleen to
oxygen gas, they became of a very bright red, while the
air losing its oxygen, became impregnated with carbon.

396. But since the spleen is the only organ of that de-
scription quite destitute of an excretory duct, excepting
its veins which run ultimately to the liver, its function
is probably subservient to that of the liver. This opinion
has appeared strengthened by the observation, that in
animals deprived of their spleen, – an experiment fre-
quently made from the most remote period,* the cystic
bile is sometimes found pale and inert.

397. At least twenty hypotheses have been framed re-
specting the use of the spleen. Two more have been
lately advanced, both supposing a connection between the
spleen and stomach, but the one regarding the spleen as
a diverticulum to the blood destined to form the gastric
juice;
(A) the other, supported by excellent arguments
and experiments, making the spleen receive a great por-
tion of our drink from the cardiac extremity of the sto-
mach, so that these can pass through a short way, hitherto
unknown, from the stomach to the spleen, and thus into
[Seite 219] the mass of blood. The latter hypothesis, if a few objec-
tions were removed,* would be much the most plausible
of any hitherto constructed. (B)



NOTES.

(A) This opinion was proposed a century ago, by Dr.
Stukely, Fellow of the Royal college of physicians,
London.

(B) Mr. Home, having passed a ligature around the
pyloric extremity of the stomach of a dog, injected into
it a solution of rhubarb; and, on killing the animal some
hours afterwards, none of the absorbents of the stomach
were found distended, nor could any trace of rhubarb be
detected in the liver, but evident traces existed in the
spleen and the urine.

SECT. XXVII.
OF THE FUNCTIONS OF THE OMENTUM.

[Seite 220]

398. The omentum gastrocolicum or magnum,* (to
distinguish it from the parvum or hepato-gastricum), is
a peculiar process of peritonaeum, arising immediately
from the peritonaeum of the stomach.

399. Although there are innumerable continuations of the
peritonaeum in the abdomen, and every abdominal viscus
is so covered by it, that, on opening the abdomen, no-
thing is found destitute of that membrane; this covering,
nevertheless, is afforded in different ways, which may be
reduced to classes.

Over some the peritonaeum is merely extended, or it
affords to them only a partial covering, as with respect to
the kidneys, rectum, urinary bladder, and in some mea-
sure to the pancreas and gall-bladder.

To some which project into the cavity of the abdomen,
although adhering to its parietes, it affords a covering for
the greater part of their surface; v.c. to the liver, spleen,
stomach, uterus, and the testes of the very young foetus.

[Seite 221]

The intestinal tube, with the exception of the rectum,
projects so much in the cavity of the abdomen, that it
is, as it were, suspended in loose processes of the perito-
naeum, called mesentery and mesocolon: the broad liga-
ments of the uterus are similar to these.

400. The longest and most remarkable process of peri-
tonaeum, is the omentum, – a large, empty, delicate, sac,
hanging from the large curvature of the stomach, extended
over the greater part of the small intestines, applying
itself closely to their convolutions, and in some measure
insinuating itself into their interstices.

401. Besides the blood-vessels seen upon the omentum,
it is marked by fatty striae or bands, every where reticu-
lated (whence the common appellation of this membrane),
which in corpulent persons increase occasionally to a large
and even dangerous size, and by means of which the
whole omentum is lubricated by an adipose halitus.

402. On the latter circumstance depends the use com-
monly ascribed to the omentum, – of lubricating the intes-
tines and assisting their continual movements: this also
appears the use of those analogous small bursae which
are found* in such numbers about the rectum and
colon. The omentum also prevents the adhesion of the
intestines to the peritonaeum, and the consequent impedi-
ment to the functions of the primae viae.

403. There is another two-fold office attributed with
[Seite 222] great probability to the omentum;* viz. that of facilitating
the dilatation of the viscera to which it is contiguous, and
of acting as a diverticulum to their blood during their state
of vacuity.

404. If we reflect on the singular structure of the omen-
tum parvum or hepato-gastricum especially, we may be in-
clined to believe that there is another and principal
office attaching to it, unknown at present, and discover-
able by comparative anatomy.

SECT. XXVIII.
OF THE FUNCTION OF THE INTESTINES.

[Seite 223]

405. The intestinal tube, over which the omentum is
extended, and which receives the chyme to elaborate it
farther (362, 363) and separate the chyle from the faeces,
is divided into two principal portions, – the small and
large intestines, of whose functions we shall speak sepa-
rately.

406. The small* intestines are again divided into
three; the duodenum, jejunum, and ileum.

The first is named from its usual length.

The second from generally appearing collapsed and
empty.

The third from its convolutions: it is the longest of the
three, fuller, and, as it were, inflated, and sometimes
resembling the large intestines by the appearance of
bullae.

407. The coats of the small intestines correspond with
those of the stomach (354).

The external is derived from the mesentery.

The muscular consists of two orders of fibres: the one
longitudinal, interrupted, external, and found especially
[Seite 224] about the part opposite the mesentery; the other, annu-
lar and falciform, possessing the power of narrowing the
canal, while the former shortens it. Upon both depends
the very great and permanent irritability of the intestines,
formerly mentioned (300).

The nervous coat is condensed cellular membrane,
easily reduced by handling, or more particularly by infla-
tion, into a spumous tela;* in it the intestinal blood-
vessels run to the mesenteric in a beautiful arborescent
form; the intestines, no less than the stomach, are in-
debted to it for their tenacity and strength.

The interior, lined by its delicate epithelium, and de-
serving the name of villous in the small intestines more
than in any other part of the canal, forms, in conjunction
with the inner surface of the former coat, here and there,
undulated ridges and rugous plicae, which, in dried and
inflated intestines, resemble the edge of a scythe, and
are termed the valvulae conniventes, or Kerkringhianae.§

408. The villi, which are innumerable upon the inner
surface of the intestines, and whose beautiful and minute
vascular structure was first carefully investigated, though
described with exaggeration, by Lieberkühm,** may be,
[Seite 225] per aps, compared, while destitute of chyle, to little
loose pendulous bags, internally soft and spongy; but
when distended with chyle, they have the appearance of
a morel.

409. The base of these villi is surrounded by innume-
rable glandular follicles, adhering chiefly to the nervous
coat, and opening into the intestinal canal by a very
small orifice through which they discharge the mucus
which lines the whole tract of the intestines.

These are distinguished into three orders. The Brun-
nerian, largest, distinct, found in most abundance in that
part of the duodenum which is contiguous to the pylo-
rus.* The Peyerian, smaller, aggregated, found chiefly
at the termination of the smaller intestines, about the valve
of the colon. Lastly, the Lieberkühnian, the smallest,
said to be distributed in the proportion of about eight to
each villus. The two former orders are so inconstant,
that I am inclined to consider the view given of them in
the plates alluded to, as morbid;§ for I have more than
once been unable to discover the slightest trace of fun-
gous papillae with a single pore, in the small intestines
[Seite 226] of healthy adults; while, on the contrary, in aphthous
subjects, I have found nearly the whole intestinal tube
beset with them in infinite numbers, both solitary and
aggregated.*

410. As the gastric juice is poured into the stomach,
so an enteric or intestinal fluid is poured into the small
intestines, demonstrated, among other ways, by the com-
mon experiment, first, I believe, instituted by Pechlin.
It is probably of a nature similar to the gastric liquor,
but an accurate investigation of it is a physiological desi-
deratum. I can say nothing respecting its quantity, but
the estimation of Haller is certainly exaggerated, – at
eight pounds in the twenty-four hours.

411. The intestines agree with the stomach in this par-
ticular, that they have a similar, and indeed a more un-
questionable, or, at least, a more lively, peristaltic action,
which occurs principally when the chymous pulp enters
them. This it agitates by an undulatory constriction of
different parts of the canal, and propels from the duode-
num towards the large intestines. Although the existence
of an antiperistaltic motion, causing a retrograde course
to their contents, cannot be disproved, it is in health
much weaker, and less common and important than the
former.

412. By these moving powers and by these solvents
which are afforded by means of secretion, the chyme
[Seite 227] undergoes remarkable changes.* In the jejunum it be-
comes a more liquid pulp, equally mixed, of a grey
colour, and acidulous odour: in the ileum, it begins to
separate into two parts, – into the faeces, of a pale yellowish,
brown colour, and nauseous smell; and the genuine
chyle, swimming upon the former, extracted from the
chyme, separated by the bile from the faeces, and des-
[Seite 228] tined for absorption by the lacteal vessels, as we shall
find in the next section (A). At present we shall enquire
what course is taken by the faeces.

413. These, after becoming more and more inspissated
in their long course through the ileum, have to overcome
the valve of the colon and pass into the large intestines.
To facilitate this, the extremity of the ileum is lubricated
very abundantly by mucus.

414. The valve of the colon,* or, as it may deservedly
be termed after its discoverer, the valve of Fallopius,
is a short process or continuation of the part of the ileum
penetrating into the cavity of the large intestine, which
[Seite 229] surrounds the former. Its external lips, while a neigh-
bouring fold of the large intestine at the same time pro-
jects considerably, are constituted* not like other similar
folds, merely of the interior and nervous coats, but of
fibres from the muscular coat. Hence it performs the
double office of preventing too great a quantity of faeces
from passing from the small into the large intestines, and
of preventing regurgitation from the latter.

415. The large intestines, divided like the small into
three parts, commence by the coecum (which has a ver-
miform process,
whose use in man is unknown) and
afford a very ample receptacle, in which the faeces may
be collected and retained till the period of their discharge
arrives.

416. They exceed the small intestines in thickness and
strength, as well as in capacity. The muscular coat has this
peculiarity, – that its longitudinal fibres, excepting at the ex-
tremity of the rectum, are collected into three bands, called
ligaments of the colon; and the intestines themselves are
divided into a kind of prominent cells. The inner coat is
not so beautifully flocculent as in the small intestines, but
more similar to that of the stomach.

417. Their peristaltic motion is much fainter than that
of the small intestines. On the other hand, they experi-
[Seite 230] ence to a greater degree the pressure of the abdominal
parietes, to which the whole length of the colon is con-
tiguous.

418. They gently propel the faeces into the rectum,
which thus becomes internally stimulated to discharged its
contents. This is facilitated by the absence of transverse
rugae, and especially by the great quantity of mucus at
the extremity of the bowels.

419. The discharge of faeces is principally effected by
the pressure of the abdomen downwards, overcoming the
resistance of the os coccygis and of both sphincters, the
inner of which is a remarkable bundle of circular fibres;
and the outer, a truly cutaneous muscle. After the ex-
cretion, the effort of the abdomen having ceased, the
levator ani retracts the intestine, which is again closed by
its sphincter.*



NOTE.

(A.) A great part of the chyle is generally formed
and absorbed before the digested mass reaches the
ileum. See Annals of Med. and Surgery, Vol. i. p. 144.
On arriving in the large intestines, the mass undergoes
fresh changes, at present unexplained, and is converted
into excrement. Here it is that the true succus entericus
must be poured forth.

SECT. XXIX.
OF THE FUNCTION OF THE ABSORBENT VESSELS.*

[Seite 231]

420. The chyle which we left in the ileum just sepa-
rated from the faeces, must evidently be a mixture of dif-
ferent fluids. The proportion derived from the secretions,
– the saliva, bile, the gastric, pancreatic, and enteric
fluids, surpasses, without the least doubt, that which is
derived from the aliment, although it cannot be accurately
ascertained. Hence must be obtained the solution of the
problem, – how injesta of such various kinds can be con-
verted into the chyle – a fluid constantly of the same ap-
pearance, homogeneous, and of an animal nature.

421. The course of the chyle from the intestines to the
blood, is through a part of the absorbent system, which
we have hitherto only hinted at, but shall now speak of
particularly. It is divided into four parts, – lacteal and
lymphatic vessels, conglobate glands, and the thoracic
duct. Each of these will now fall under consideration.

422. It is certain that the lacteals originate among the
villi of the internal coat of the intestines; but whether
they are an immediate continuation of these villi, or
merely connected with them by a cellular medium, admits
a question. I myself have never been able to trace them
[Seite 232] so far as to discover their immediate connections with the
villi, but they appear to arise here and there in the coats
of the intestines, by a conspicuous trunk, and we may
conjecture that they take up the chyle from the cellular
structure into which it is first drawn by the villi. This I
have in fact observed repeatedly in puppies, after making
them swallow a solution of indigo, according to the cele-
brated experiment of Lister,* an hour or two before
opening them alive.

423. The trunks just mentioned run some inches along
the surface of the intestines, under the external coat,
sometimes meandering in an angular course, before they
reach the mesentery.

424. In their course through the mesentery they run
into the mesenteric glands, of which there are two series.
The one, nearer the intestines, dispersed, small, and re-
sembling beans in shape; the other, nearer the recepta-
culum chyli, large, and aggregated.

425. Both appear nothing more than closely-compacted
collections of lacteals, interwoven with innumerable blood-
vessels, and retarding the course of the chyle; to the
end, perhaps, that it may be more intimately and per-
fectly assimilated to an animal nature, previously to its
entrance into the thoracic duct and its mixture with the
blood.

426. It has been inquired whether lacteals exist also in
the large intestines, and their existence has been contended
for from the effects of particular injections, nutrient,
inebriating, &c. and also by the circumstance that the
[Seite 233] faeces, if retained for any length of time, become hard and
dry. Although these arguments do not demonstrate the
absorption of genuine chyle below the valve of Fallopius,
nevertheless it is rendered probable by the visible exist-
ence of an abundance of lymphatics in the large intes-
tines,* having the same structure and function with the
lacteals; for these absorb lymph from the intestines,
during the absence of chyle.

But the very different structure of the internal coat of
the large intestines from that of the villous coat of the
small, strongly argues that they are not naturally intended
to absorb chyle.

427. There is another question more important and
difficult of solution, whether all the chyle absorbed from
the small intestines, passes through the thoracic duct,
or whether some enters the blood by other more secret
passages?

The latter opinion rests upon very unstable arguments.
Thus the assertion of Ruysch, that the mesenteric glands
become, in advanced life, indurated and unfit for con-
tinuing their functions, was long since disproved; and
affections of these glands, swellings, &c. are improperly
called obstructions, as the glands remain pervious, rea-
dily allowing a passage to quicksilver. The well-known
phenomenon of tepid water injected after death into
the mesenteric veins, passing into the cavity of the intes-
tines, has little weight with me in regard to a function
which occurs during life; and much less weight can be
[Seite 234] allowed to the bifurcated brass tube invented by Lieber
kühn to prove the existence of these passages. The
assertion, that chyle has been seen in the mesentric veins,*
requires farther investigation and proof; so that I cannot
believe that they carry any thing more than blood, very
carbonised, and destined for the formation of bile.

428. The ultimate trunks of the lacteals, arising, like
the other lymphatics, from the combination of a great
number of small twigs, unite into the receptaculum or
cysterna chyli, – the appellation by which the lower and
larger part of the thoracic or Pecquetian duct is distin-
guished.

[Seite 235]

429. This duct is* a membranous canal, slender, strong,
more or less tortuous, subject to great varieties in its
course and division, destitute of muscular fibre and
nerves, and possessing here and there valves. At about
the lowest cervical vertebra, after passing the subclavian
vein, it turns back again, and is inserted into it, being
furnished with a peculiar valve at the point of insertion.

430. The motion of the chyle throughout its course is
to be ascribed to the contractility of its containing vessels,
to their valves, and the vis-a-tergo.

431. The use of the valve placed at the opening of the
thoracic duct, is probably not so much to prevent the
influx of blood, as to modify the entrance of the chyle
into the vein, – to cause it to enter by drops.

By this contrivance, such a portion of fresh chyle cannot
have access to the blood as would stimulate the cavities
of the heart too violently, and be imperfectly and diffi-
cultly assimilated; for fresh chyle consists of very hete-
rogeneous elements, brought not only from the primae
viae by the lacteals, but from every part of the body by
the lymphatics.

432. These lymphatics,§ which constitute the third part
[Seite 236] of the absorbent system, and resemble the lacteals in
structure and function, are much more, and perhaps, in-
deed, universally, diffused.* They arise principally from
the mucous web, which we therefore called the grand
bond of connection between the sanguiferous and absorb-
ing system (27); but in great numbers likewise from the
external common integuments, from the fauces and oeso-
phagus (330), the pleura and peritonaeum, and from the
thoracic and abdominal viscera.

433. Their origin is similar to that of the lacteals in
the intestines, so that the radicle of each lymphatic ab-
sorbs the fluid from the neighbouring cellular membrane,
as from its territory, and propels it onwards.

434. The lymphatics have double valves, set more or
less thickly in different parts; they all enter conglobate
glands; those which are contiguous to each other, anas-
tomose here and there; and those found on the surface
of certain viscera, as the lungs, liver, &c. form a most
beautiful network.

435. Besides other assistances to their functions, evi-
dent from what has already been said, no inconsiderable
assistance is derived from the combination of great strength
with thinness in their coats, by which they are enabled to
support a heavy column of quicksilver. In the limbs,
especially, the motion of the muscles pressing them on
every side, is highly useful in increasing their power.

436. But their principal action, by which they take up
fluids more or less rapidly, eagerly absorbing some, and
[Seite 237] absolutely rejecting others,* depends upon the peculiar
modification of their vitality, and is ascribed by the very
acute Brugmans to a certain vita propria. (42)

437. The far greater part of these lymphatics terminate
in the thoracic duct; except, however, those of the right
arm, the right side of the neck, the right lung, and the
right portion of the diaphragm and liver, which terminate
in the subclavian vein of the same side.

438. From the universal existence of the lymphatics,
and especially from the great numbers on the surface,
capable of absorbing fluids from without, the heteroge-
neous nature of the lymph must be obvious; and this is
further proved by accurately examining it in different
parts of a subject; v.c. that contained in the hepatic
or splenic lymphatics is perfectly different from that in
the uterine.

439. We will enumerate the principal fluids which are
continunally absorbed during health, to say nothing of
many different kinds of substances taken up during dis-
ease. There is, besides the chyle separated from the
faeces in the small intestines, the halitus of the cavities
properly so called, especially that of the fauces and the
whole mucous web, the fat, the more watery part of those
secreted fluids which are retained for some time in their
[Seite 238] ducts, v.c. of the milk, semen, bile, &c. and not a small
portion of the fluids in contact with the surface.*

440. The solids, after performing their purpose in the
economy, insensibly melt away and are absorbed, as is
proved by the absorption of the greater part of the thymus
gland during infancy, of the roots of the first teeth, and of
the alveoli after the second teeth have fallen out. The
constant change of the whole osseous system, arising
from the insensible renovation of the bony matter, of
which we have treated elsewhere professedly, may also
be adduced.

441. It is therefore evident, since so great a variety of
matter is absorbed, and at the same time nothing crude
or imporper allowed to enter the blood, that there is a
necessity for some peculiar medium for previously sub-
acting and assimilating the various substances.

442. It appears to be the chief office of the conglobate
glands,
which constitute the last part of the absorbent
system, to prevent the ill effects, upon the heart, of the
improper admixture of crude fluids with the blood, by
[Seite 239] assimilating the various fluids, particularly those absorbed
by the skin, more and more to an animal nature, by re-
tarding their motion, and perhaps also by superadding to
them some fresh secreted fluid.(A)

443. As to the rest of those glands dispersed generally
through the body, and aggregated here and there, as in
the groin and axillae, they are perfectly similar to those
found in the mesentery, consisting, like them, in a great
measure, of convoluted absorbent vessels, supplied with
an immense number of blood vessels, and liable to the
same diseases.*



NOTE.

(A) Although some albumen is discovered actually in
the duodenum, and some fibrin in the first lacteals, the
chyle is found to contain more and more of these substances,
in proportion to its progress towards the left subclavian
vein. The chyle contains a certain fatty matter, which is
considered as incipient albumen, and in proportion as this
decreases, does the quantity of fibrin and albumen in-
crease. Annals of Med. and Surgery. Vol. i. p. 144.

SECT. XXX.
OF SANGUIFICATION.

[Seite 240]

444. There is scarcely occasion to remark that we
employ the term Sanguification to denote the assimilation
of the chyle to the blood, and the successive reparation,
by means of the former, of the successive loss sustained
by the latter.

445. The division of all our fluids into three classes
(45), crude, sanguineous and secreted, turns upon this; that
the middle class contains the stream of the vital fluid it-
self, from which the numerous secreted fluids are perpe-
tually withdrawn, and to which, on the other hand, there
is a constant afflux of chyle and lymph from the absorb-
ent system.

446. But since the blood is a peculiar fluid, sui generis,
without its fellow in nature, various assistances and media
are evidently requisite to subact and assimilate the he-
terogeneous and foreign fluids which pass to it from the
thoracic duct.

447. This is, in the first place, especially in the mesen-
teric and other conglobate glands, favoured by those wind-
ings, mentioned formerly, of the lacteals and lymphatics,
which are, at the same time, gradually more impregnated,
as it were, with an animal nature.

448. We must also take into consideration, that a great
part of the lymph which enters the left subclavian after its
[Seite 241] admixture with the intestinal chyle in the thoracic duct,
has been derived from the substance of the viscera and
other soft parts, formerly secreted from the blood, and,
therefore, already imbued with an animal nature, and
easily, without doubt, again miscible with the mass of
blood, to which it does but return.

449. Something is contributed by the slow and almost
stillatitious manner in which the chyle drops into the
blood through the last valve of the thoracic duct, these
very minute portions becoming the more intimately com-
bined with the blood.

450. The heart, too, by means of the remarkable papil-
lary muscles of the ventricles, agitates and mingles the
blood just impregnated with fresh chyle.

451. The great importance of the lungs which receive
the blood immediately after its addition of fresh chyle, and
also of respiration, in the business of assimilation,* will be
evident on considering the extraordinary vascularity of
those organs (14), and their constant and regular motion.

452. The remaining part of sanguification is accom-
plished by the general circulation and the powers which
assist it, particularly by muscular motion, &c.

453. Although so many means are provided for the
combination of the chyle with the blood, and although the
constituents of the chyle somewhat resemble those of this
fluid; nevertheless, it is commonly asserted, that many
hours are required for the complete change of the colour
[Seite 242] of the chyle and its assimilation. Besides other arguments
in favour of this assertion, the pathological fact is urged,
that chyle is frequently seen in blood drawn many hours
after digestion. I myself have witnessed this appearance
in cases where the blood too evidently bore an inflam-
matory disposition, to use a common phrase; but I am
persuaded that no inference can be hence drawn, in re-
gard to the healthy state, which alone is the object of
physiology.

SECT. XXXI.
OF NUTRITION.

[Seite 243]

454. Besides the function of the blood formerly in-
vestigated – of distributing oxygen through the system
and removing carbon, its principal use is to afford nourish-
ment to the body in general, and to the secreting organs
the peculiar fluids which they possess the power of deriv-
ing from it. Nutrition shall be first examined.

455. Nutrition is the grandest gift of nature, and
the common and highest prerogative of the animal and
vegetable kingdoms, by which these, beyond all measure,
surpass, even at first sight, all human machines and auto-
mats. Upon these no artist can bestow the faculty, not to
say of increasing and of coming to perfection, but even
of existing independently and repairing the incessant
losses incurred from friction.*

456. By the nutritive faculty of the body, its greatest
and most admirable functions are performed; by it we
grow from the first of our formation and arrive at man-
hood; and by it are remedied the destruction and con-
[Seite 244] sumption which incessantly occur in our system during
life.*

457. Respecting the nature of this consumption, it has
been greatly disputed, whether it affects the solids, or
whether, according to some very acute writers, these,
when once formed and perfected, remain invariably en-
tire.

458. There can be no doubt that some of the similar
solids, v.c. the epidermis and nails, are gradually de-
stroyed and renewed; and the same is proved respecting
even the bones by the well known experiment of dying
them with madder root; (A) and by the frequently re-
markable attenuation of the flat bones, especially of the
skull, from defective nutrition in old age.§

459. If I am not mistaken, those solid parts undergo
this successive change, which possess the reproductive
power,
– an extraordinary faculty, by which not only the
natural loss of particles, but even the accidental removal
of considerable parts, from external injuries, is repaired
[Seite 245] and perfectly supplied, as the bones* and a few other
parts sufficiently demonstrate.

460. On the other hand, I have been led by many ex-
periments to the conclusion, that this genuine reproductive
power
appears completely bestowed upon no similar parts
which possess any other vital power besides contractility,
i.e. irritability, sensibility, or a vita propria.

461. In these parts, therefore, whose vital powers are
of an higher order, the parenchyma constituting their base,
appears permanent, and is liable to this change only, –
that the interstices of the fibres and parenchyma, while
nutrition is vigorous, are constantly full of nutrient animal
gelatine; but, when nutrition languishes, are deprived of
their gelatine, collapse, and consequently become thin.

462. For as the plastic lymph, the importance of which
has been frequently mentioned, is readily converted into
cellular membrane, so it appears to constitute the principal
material of the body, and, as it were, the animal gluten,
which is nourished by its means.

[Seite 246]

463. During the growth of the body, peculiar powers
are exerted, by which the lymph deposited in the cellular
membrane by the blood vessels is properly distributed and
intimately assimilated to the substance of each organ, &c.
This is referrible, both to the laws of affinity, by which
particles attract, and, as it were, appropriate others which
are similar and related to themselves; and to the nisus
formativus, which we shall enlarge upon hereafter, and to
which the proper applification of shapeless elementary
matter, and its modification to particular forms, must be
ascribed.

464. To both these powers, we conceive, must be parti-
cularly attributed the nutrition of such similar parts as
are not supplied with blood; but are, nevertheless, at first
generated by a most powerful and infallible nisus, grow,
are nourished, and, if destroyed by accident, are very
easily reproduced;* such are the nails, hairs, &c.

465. As this appears to be the true account of nutrition
in general, so, on the other hand, it evidently has great
varieties of degree and kind, especially where, from the
more or less lax apposition of the nutritious matter, the
structure of the similar parts is more or less dense, and
the specific weight of the whole body more or less con-
siderable. In this respect, not only individuals, but whole
[Seite 247] nations differ from each other. The Jakats and Burats,
who are remarkable for the lightness of their bodies, are a
sufficient example of this.



NOTE.

(A) The redness imparted to the bones by feeding
animals with madder, does not prove that the matter of
the bones is constantly changing; because the opinion
that the madder unites with the phosphate of lime in the
blood, and thus reddens all the bony matter subsequently
deposited, is erroneous. Mr. Gibson proved, by numerous
experiments, that the serum has a stronger affinity than
the phosphate of lime for madder. The serum being
charged with madder, the phosphate of lime of the bones,
already formed, seizes the superabundant madder and be-
comes red. If the madder is no longer given to the
animal, as it is continually passing off with the excretions,
the stronger attraction of the serum draws it from the
bones, and they re-acquire their whiteness. Manchester
Memoirs,
vol. i.

SECT. XXXII.
OF THE SECRETIONS IN GENERAL.

[Seite 248]

466. Besides the nutritious fluids, others of various
descriptions are produced from the blood by means of
secretion, which Haller, no less than his predecessors, with
truth and regret declared to be among the most obscure
parts of physiology.*

467. The secreted fluids on the one hand differ so con-
siderably among themselves, and on the other, have so
many points of resemblance, that their classification cannot
but be extremely arbitrary. If we arrange them ac-
cording to the degree of difference between them and the
blood from which they are formed, they will stand in the
following order:

First, the milk, which may be in some degree considered
as chyle reproduced, and appears formed by the most sim-
ple process from the blood newly supplied with chyle.

Next, the aqueous fluids, as they are commonly deno-
minated from their limpid tenuity, although the greater
part differ importantly from water in the nature of their
[Seite 249] constituents, and especially in the proportion of albumen:
such are the humours of the eye, the tears, in all proba-
bility the vapour contained in the cellular interstices and
the cavities of the abdomen and thorax; nearly similar,
also, is the fluid of the pericardium and of the ventricles
of the brain.

The liquor amnii of pregnancy, and the urine remarkable
for the peculiar nature and mixture of its proper consti-
tuents, are generally enumerated among these.

The salivary fluids, concerned in mastication, digestion,
and chylification, appear more elaborated.

Next the mucous, which line the cavities of most of the
organs performing the natural and genital functions, and
likewise the tract of the nostrils, larynx, and trachea.

The mucus within the eye, and under the epidermis, is
nearly similar.

In the same class may be included the cerumen of the
ears, the unguent of the Meibomian glands, and of the
joints, and, perhaps, the nameless fluid poured forth into
the vagina during the venereal oestrum.

The adipose are, besides the common fat, the medulla
of the bones and grease of the skin.

Related to these are the secretion of the corona glandis
under the preputium, and of the external female genitals.

The truly serous, or albuminous, are the fluid of the
ovarian vesicles of De Graaf; and the liquor of the
prostate.

The semen virile and the bile are each sui generis.

468. It is obvious that so great a variety of secreted
fluids cannot be secreted from the mass of blood in the
same way, nor by similar organs. Their chief distinction
is the simplicity or complexity of their preparation.

469. The most simple mode of secretion is diapedesis,
[Seite 250] or transudation; which is the case with the fat and the
bony fluid.*

470. Secretion by glands is more complicated. Such
is considered the secretion even by follicles and cryptae
found, v.c. in some parts of the corium, the fauces, and
aspera arteria, and denominated the most simple glands.

Properly speaking, the conglomerate (as they are called
to distinguish them from the lymphatic conglobate) are
the only true secreting organs; such as the salivary and
lachrymal glands, the pancreas and breasts. They are
provided with an excretory duct coming immediately
from the large lobes which are composed of others,
smaller, and so intricate in their structure, as to have been
the source of warm disputes in the schools of medicine.
[Seite 251] Malpighi* considered the miliary globules, which are
easily discoverable in most glands, as acini internally
excavated. Ruysch, on the contrary, contended that
these supposed hollow acini were nothing more than
glomerules of blood vessels, – an opinion far more con-
sistent with microscopical observation and the effects of
minute injection.

471. The structure of some secreting organs, especially
of the liver and kidnies, the latter of which strikingly
exhibit the glomerules of Ruysch or the acini of Mal-
pighi, are not, excepting in their peculiar parenchyma,
very dissimilar from this structure, and indeed throw con-
siderable light upon the question. On the outer part of
these, small twigs arise from the sides of the capillary
arteries and run into vascular glomerules, hanging like
granules as from stalks; from these arterial glomerules
spring very minute colourless secreting vessels, whose
origin from the extremities of arteries, was formerly al-
luded to (92); and the radicles of veins into which the
arteries are continued, and which convey back into the
venous trunks the remaining blood deprived of the se-
creted fluid.

472. The organization of some other secreting parts is
evidently peculiar, v.c. of the testes, which are composed
of very long and numerous vessels, closely compacted,
&c.

473. That the different nature of the secreted fluids
depends not so much on the size and external form of the
[Seite 252] secreting organs as upon their interior structure and cor-
responding vital powers, is rendered probable by the
example of many of our fluids, which, although secreted
by organs at first sight very different from each other,
have considerable resemblance to each other in nature;
v.c. the saliva and gastric juice. And comparative
anatomy teaches us, that the same fluids are formed by
organs very different in external appearance, in different
animals.*

474. We shall now investigate the causes why par-
ticular fluids are found in particular organs, – the most
difficult part of the doctrine of secretion, and still open to
many doubts.

475. There can be no question that the absolute cause
of the variety of secretions is referrible to the intimate
nature of the secreting organ. This depends, in the con-
glomerate glands and secreting viscera especially, both
upon the direction and distribution of the secreting blood
vessels, and upon the peculiar parenchyma of each secret-
ing organ, in some instances distinguishable at first sight
from the substance of every other part (20).

476. It is likewise probable, and indisputable argu-
ments in favour of the opinion have been continually af-
forded in the course of this work, that secreting organs
have not only a peculiar parenchyma, but a vita propria,
viz. a singular species of vitality distinct from the com-
mon vital powers of contractility, irritability, and sensi-
bility.

[Seite 253]

477. The absorbent system seems of much importance
in the business of secretion. In every secreting organ, it
absorbs and conveys to the blood a fluid which is, as it
were, contaminated by the secretion of the part: v.c. a
bilious fluid in the liver; a spermatic in the testes.
A constant circle would, therefore, appear to exist in the
secretory system, so that the elements of the secretions
are incessantly carried to the blood from the secreting or-
gans, and when they have returned to the organs are the
more easily attracted by a species of affinity, and draw
with them those parts of the blood whose nature is re-
lated to their own.

478. The blood from which some secretions are pro-
duced, is endowed with peculiar qualities. The bile, for
example, is derived from blood which contains an abund-
ance of carbonaceous element.

479. We omit other assistances afforded to certain
secretions; v.c. congestion and derivation, so striking in
the secretion of milks, &c.

480. There is this difference between the different fluids
secreted by the organs and powers now described, – that
some pass to the place of their destination immediately,
while others are deposited in receptacles, and detained
there for some length of time, becoming more perfect
previously to their excretion. The milk in its ducts, the
urine, bile, and semen in their respective bladders, and
the serum contained in the vesicles of De Graaf, are
examples of this. (A)

NOTES.

[Seite 254]

(A) ‘“There are two classes of secreted fluids, viz. the
secretions, properly so called, or the fluids intended to
fulfil some ulterior purpose in the animal economy, and
the excretions, which are directly discharged from the
body. The fluids of the former class are all alkaline, and
of the latter all acid. The excretions are the urine, the
perspired fluid, and the milk. All the other fluids appear
to belong to the former class.’

‘“The alkaline secreted fluids may be divided into two
very distinct species. The former of these contains the
same quantity of water as the blood, so that the changc
induced by the nervous influence, seems to be confined to
that of altering the chemical form of the albuminous ma-
terials,* without affecting their relative proportion to the
water and other substances dissolved in the blood. The
bile, spermatic fluid, &c. are of this kind. The latter
species consists of fluids, in which the influence of the
nervous system has separated a large portion of the albu-
minous matter, and left the remaining liquid propor-
tionally watery. The saliva, the humours of the eye, and
the effused serum of membranes, are of this species, and
in these the quantity of salts, and in general also of alkali,
is the same as in the blood.’

‘“The influence of the chemical agent of secretion is,
therefore, chiefly spent upon the albuminous materials of
the blood, which seems to be the source of every substance
that peculiarly characterises each secretion, each of which
[Seite 255] is sui generis, and is its principal constituent. All the
other parts of the secretion seem to be rather accidental,
and to be found there only because they were contained
in the blood out of which the secretion was formed.
Therefore, in examining the secreted fluids, the chief
attention should be paid to the peculiar matter of the
fluid, which varies in all. This matter sometimes retains
some of the properties of albumen, at other times, none:
and hence an acurate analysis, shewing the quantity and
nature of this peculiar matter, is above all to be desired.’

‘“If the several secretions be supposed to be deprived of
their peculiar matter and the remainders analysed, the
same residue would be found from them all, which also
would be identical with the fluid separated from the
serum after its coagulation. Thus we should find, first, a
portion soluble in alcohol, consisting of the muriates of
potash and soda, lectate of soda, and of an extractive
animal substance, precipitable by tannin; and secondly,
of a portion soluble only in water, containing soda (which
acquires carbonic acid by evaporation, and is separable
by acetic acid and alcohol) and another animal substance,
not extract, precipitable from its solution in cold water,
both by tannin and muriate mercury. Sometimes a
vestige of phosphate of soda will also be detected.’

‘“The excretions are of a more compound nature. They
all contain a free acid, which is termed lactic, and in the
urine this is mixed with the uric acid. Urine seems to
contain only a single peculiar characteristic matter; but
milk has as many as three, viz. butter, curd, and sugar of
milk, which, however, seem to be produced by different
organs that mingle their fluids in the same receptacle.
The perspired fluid appears to have no peculiar matter,
but to be a very watery liquid, with hardly a vestige of
[Seite 256] the albumen of the blood, and, in short, is the same as the
other excretory fluids would be when deprived of their
peculiar matter. If we suppose this matter taken away
from those excretions which possess it, the remaining
fluid will be found to have properties very different from
the fluid part of the secretions, when equally freed from
their peculiar matter. That of the excretions is acid, con-
tains earthly phosphates, and when evaporated, leaves a
much larger residue than the fluid of the secretions. This
resieue is yellowish-brown, of the consistence of syrup,
with an unpleasant sharp saline taste of the salts that it
contains. It reddens litmus, is most soluble in alcohol,
and this spirituous solution contains the muriates of the
blood, together with free lactic acid, much lactate of soda
(the soda being the free alkali of the blood, neutralised
by this acid), and the extractive matter, which always ac-
companies this neutral salt. The part insoluble in alcohol
contains a distinguishable quantity of phosphate of soda,
a little of a similar animal matter to that found in the
secretions, and also the earthly phosphates which were
held in solution by the lactic acid, and were precipitated
by the action of the alcohol. The urine possesses also a
number of other substances, which will be specified when
describing this excretion in particular.”’*

SECT. XXXIII.
OF THE FAT.

[Seite 257]

481. Of most of the secreted fluids, a concise and con-
nected view of which was given in the last section, distinct
mention has been made in its proper place: the rest shall
be described as opportunity may permit. Two remain,
which cannot be discussed in a more proper place than
the present, – at the close of our inquiry into the natural
functions. The one, – the fat, is a part of the system (4);
the other, – the urine, is excrementitious. Each shall be
separately examined.

482. The fat* is an oily fluid, very similar in its general
character to vegetable oils, bland, inodorous, lighter than
water; containing, besides the two elements common to
water, the oils just mentioned, and to wax, viz. carbon
and hydrogen, sebacic acid, which is pretty similar to
the benzoic.

[Seite 258]

483. When secreted from the blood and deposited in
the mucous tela, it exists in the form of drops, divided by
the laminae of the tela, in a manner not unlike that in
which the vitreous humour of the eye is contained in very
similar cells.

484. The relation of fat to different parts is various.
In the first place, some parts, even those whose mucous
tela is extremely soft and delicate, never contain fat.
Such are the palpebrae and penis.

In very many parts, it is diffused indefinitely, especially
in the panniculus adiposus, the interstices of the muscles,
&c.

In some few, it is always found, and appears to be
contained in certain definite spaces, and destined for par-
ticular purposes. Such I consider the fat around the basis
of the heart:* and in the mons veneris, where it forms a
peculiar and circumscribed lump.

485. Its consistence varies in different parts. More
fluid in the orbit, it is harder and more nearly resembling
suet around the kidnies.

486. It is of late formation in the foetus; scarcely any
trace of its existence is discoverable before the fifth
month after conception.

487. There have been controversies respecting the mode
of its secretion. Some, as Hunter, contending that it is
[Seite 259] formed by peculiar glands; others, that it merely tran-
sudes from the arteries. Besides other arguments in fa-
vour of the latter opinion, we may urge the morbid exist-
ence of fat in parts naturally destitute of it; a fact more
explicable on the supposition of diseased action of vessels,
than of the preternatural formation of glands. Thus, it
is occasionally formed in the orbits; a lump of hard fat
generally fills up the place of an extirpated testicle; and
steotoms have been found in almost every cavity of the
body.

The glands which some celebrated characters have
contended to secrete the fat, are at present imaginary.
Whatever may be the truth of this matter, the deposition
and absorption of the fat take place with great rapidity.

488. The use of the fat is multifarious.

It lubricates the solids and facilitates their movements;
prevents excessive sensibility; and, by equally distending
the skin, contributes to beauty.

We pass over the particular uses of fat in certain parts,
v.c. of the marrow of the bones.

During health, it contributes little or nothing to nou-
rishment.* The modern opinion has more probability, –
that it affords a receptacle for the superfluous hydrogen,
which could not otherwise be easily evacuated. (A)

NOTE.

[Seite 260]

(A) The fattest person on record is, I believe, Lambert
of Leicester. He weighed seven hundred and thirty-nine
pounds. Excessive formation of fat may be strongly op-
posed by regularly taking great exercise, little sleep, and
little, but dry food. See the instructive case of the Miller
of Billericay, in the second volume of the Transactions of
the Royal College of Physicians, London.
A large collec-
tion of cases of obesity will be found in Mr. Wadd’s
Cursory Remarks on Corpulence.

SECT. XXXIV.
OF THE URINE.

[Seite 261]

489. Besides the nutritious (4) fluids and those which
form a part of our system, others are superfluous and ex-
crementitious, commonly termed the excrements of the
second digestion, and are of two orders. The one exhaled
by perspiration, of which we treated formerly; the other,
– the urine, streaming from the kidnies.

490. The kidnies* are two viscera, situated at the upper
part of the loins on each side, behind the peritonaeum;
rather flattened; more liable than any other organs to
varieties of figure and number; suspended by the emul-
gent vessels, which are excessively large in proportion to
the kidnies; and imbedded in sebaceous fat. (485.)

491. They are enveloped in a membrane of their own
which is beautifully vascular; and each, especially during
infancy, consists of eight, or rather more smaller kidnies,
each of which again consists, as Ferrein asserts, of seventy
or eighty fleshy radii, denominated by him pyramides
albidae.

[Seite 262]

492. A kidney, if divided horizontally, presents two
substances; the exterior, called cortex; the interior, me-
dulla.

Each abounds in blood vessels, but the cortical portion
has likewise very minute colourless vessels, which secrete
the urine;* the medullary part contains those which
carry it off.

These secreting ducts arising from the arteries in the
manner formerly described, (471) are united with glome-
rules, which adhere to the cortical part and constitute the
greatest proportion of it. They may be readily dis-
tinguished by their angular course from the excreting or
Bellinian tubes, in which they terminate. These, pursuing
a strait course, run from the cortical to the medullary
substance, of which they constitute the greatest part, and
after having coalesced into fewer trunks, their mouths
perforate, like a sieve, the papillae of the pelvis of the
organ.

493. These papillae usually correspond in number with
the lobes which form the kidnies, and they convey the
urine secreted in the colourless vessels of the cortex
and carried through the Bellinian tubes of the medulla,
into the infundibula, which finally unite into a common
pelvis.

494. The pelvis is continued into the ureters, which are
[Seite 263] membranous canals, very sensible, lined with mucus, ex-
tremely dilatable, generally of unequal size in the human
subject in different parts,* and inserted into the posterior
and inferior surface of the bladder in such a way, that
they do not immediately perforate its substance, but pass
a short distance between the muscular and nervous coats,
which at that part are rather thicker than elsewhere, and
finally open into its cavity by an oblique mouth. This
peculiarity of structure prevents the urine from regurgi-
tating into the ureters from the bladder. (A)

495. The urinary bladder, varying in shape according
to age and sex, is generally capable, in the adult, of con-
taining about two pounds of urine. Its fundus, which in
the foetus terminates in the urachus, is covered posteriorly
by the peritonaeum. The other coats correspond with
those of the stomach.

The muscular consists of interrupted bands of fleshy
fibres, variously decussated, and surrounding the bladder.
These are usually called the detrusor urinae: the fibres
which imperfectly surround the neck and are inconstant
in origin and figure, have received the appellation of
sphincter.

The nervous chiefly imparts tone to this membranous
viscus.

The interior, abounding in cribriform follicles,§ is lined
with mucus, principally about the cervix.

496. The urine conveyed to the bladder, gradually be-
[Seite 264] comes unpleasant by its quantity, and, growing urgent,
inclines us to discharge it. For this purpose the urethra
is given, which varies with the sex, and will be farther
considered in our account of the sexual functions.

497. The bladder is evacuated by the constriction of the
sphincter being overcome both by the action of the detru-
sor (495) and by the pressure of the abdomen. To these
in men is superadded the action of the acceleratores,
which force out even the drops of urine remaining in the
bulb of the urethra.

498. The nature of the urine varies infinitely* from
age, season of the year, the length of the period since
food or drink was taken, the quality of the ingesta, &c.
The urine of an adult, recently made after a tranquil re-
pose, is generally a watery fluid of a nidorous odour and
of a lemon colour, which qualities depend on a peculiar
uric substance, besides a variety of other matters held by
the water in solution and differing in proportion in dif-
ferent persons. There is a remarkable quantity of phos-
phoric acid united with other constituents, forming phos-
phates of soda, ammonia, and lime. A peculiar acid, – the
lithic or uric, is found in the urine alone.§ (B)

NOTES.

[Seite 265]

(A) Mr. Charles Bell has lately described two long
muscles, running from the back of the prostate gland to
the orifices of the ureters. Their action is not only to
assist in emptying the bladder, but to pull down the
orifices of the ureters, thus assisting to preserve that obli-
quity of insertion which the ureters lose in proportion as
the bladder is depleted. – Med. Chirurg. Trans. Vol. III.

(B) The following is Berzelius’ analysis of urine, in the
Med. Chirurg. Trans. Vol. III.

Water 933.00
Urea 30.10
Sulphate of potass 3.71
Sulphate of soda 3.16
Phosphate of soda 2.94
Muriate of soda 4.45
Phosphate of ammonia 1.65
Muriate of ammonia 1.50
Free lactic acid
Lactate of ammonia
Animal matter soluble in alcohol, and
usually accompanying the lactates
Animal matter insoluble in alcohol
Urea, not separable from the preceding



} – 17.14
Earthy phosphates with a trace of fluate of lime 1.00
Uric acid 1.00
Mucus of the bladder 0.32
Silex 0.03
–––––––
1000.00
–––––––

SECT. XXXV.
OF THE GENERAL DIFFERENCES OF THE SEXES.

[Seite 267]

499. The functions hitherto examined are common to
both sexes, but some are performed very differently in
each. The most prominent differences shall be briefly
reviewed previously to examining the sexual functions,
properly so called.*

500. In general, each sex has its peculiar form; more
or less striking after birth, but not very obvious in the
young foetus: for the genitals of the male and female, at
this period, are not at first-sight different, on account of
[Seite 268] the clitoris being remarkably large,* and the scrotum
scarcely visible. (A)

501. During infancy, the general form is but little dif-
ferent, but becomes more so as age advances; when the
round and plump breasts, the general conformation, the
delicacy, softness, and the proportionally low stature of
the female, form a striking contrast with the sinewy and
robust body of the male.

502. The relation of parts, in well-formed females, is
somewhat different from that in the male. For instance,
in the female the face is proportionally smaller; the abdo-
minal and lumber portion of the trunk longer; the hips
broader, not however, if well formed, broader than the
shoulders; the buttocks larger; the legs in their descent
gradually approach the knees. (B)

503. A similar difference is remarkable in the osseous
[Seite 269] system. In females, the bones are, caeteris paribus,
smoother and rounder, the cylindrical more slender, and
the flat thinner; to pass over individual differences, v.c.
the very slight prominence of the frontal sinuses, the more
elliptic edges of the alveoli, the greater narrowness of the
chest, the greater capacity on the contrary of the pelvis,
the difference of the clavicles, thigh bones, &c.* (C)

504. With respect to the soft parts, the female mucous
tela is more lax and yielding, so as to dilate more easily
during pregnancy; the skin is more delicate, and of a
clearer white, from the quantity of fat below it. The hair
of the head is commonly longer; but other parts, which
are covered with hair in men, are either quite smooth in
women, as the chest and chin; or less hairy, as the peri-
naeum; or smaller in circumference, as the pudenda;
or covered with merely a very delicate and soft down, as
the arms and legs. (D)

505. Among the particular differences of function,
must be mentioned the pulse, which is, in females, caeteris
paribus, more frequent (116); the quantity of blood too
passing to the abdomen is greater. The lungs, on the
other hand, are smaller, from the greater narrowness of
the chest, which is however more moveable above. The
os hyoides is much smaller, the larynx scarcely prominent
and more contracted, whence the voice is less grave.

506. As to the animal functions, besides the greater
abundance of nerves in the organs of generation, the general
nervous system of females is far more mobile, and the
propensity to emotion stronger. On the other hand, the
[Seite 270] muscular system is weaker, and the muscles (with the ex-
ception of the glutei, psoae, quadrati lumborum, and a
few others) proportionally smaller. (E)

507. In regard to the natural functions, the stomach
and the appetite for food, are less;* the growth of the
body more rapid; and the periods of dentition, puberty,
and full growth, earlier.

508. But by far the greatest difference exists in the
genital functions, which are intended in man for impreg-
nating, and in women for conceiving. The fuller inves-
tigation of these now remains to be prosecuted.



NOTES.

(A) Sir Everard Home has published a singular theory,
which he supports by extremely ingenious arguments,
He contends that the sex is not determined at the first
formation of the individual, but that the parts of gene-
ration are originally so situated, and of such a nature,
that they are capable of becoming either male or female
organs when the sex is subsequently fixed. His argu-
ments are the following: 1. The Testes and Ovaria lie
originally in the same situation. 2. The Clitoris is at
first of great size. 3. When the female among Mam-
malia has inguinal Mammae, so likewise has the male;
men also possess breasts. 4. The Scrotum occupies in
the male, the place occupied in the female by the Labia,
and is of the same structure with them. 5. The Nymphae
[Seite 271] of the female exactly correspond to the Preputium of the
male. 6. Twins are usually of the same sex, as if the
same cause had influenced the generative organs of each;
when they are of different sexes, it is a common remark
that they seldom breed, nature probably having been
disturbed in her operations. 7. When among black
cattle twins are produced of different sexes, that which
appears the cow is really an hermaphrodite, incapable of
breeding, and vulgarly termed a free martin; – a circum-
stance in every respect analogous to the preceding.* It may
be added, that the round ligaments of the female descend,
like the two spermatic chords of the male, to the abdo-
minal ring, and that marsupial bones exist, without any
function whatever, in the males of some marsupial ani-
mals; the bursa fabricii of the hen, and the bifid glans
clitoridis of the opossum, are examples similar to these,
and comparative anatomy furnishes many others. Per-
haps Blumenbach’s explanation is correct, – that they
occur in conformity with a general law; teleologically in
the sex, where they are useful, and physico-mechanically
in the other. And this explanation is confirmed by the
existence in some kinds of animals, of parts which are of
no use to them, but exist for useful purposes generally in
animals of that description.

The sex of the offspring would appear determined by
the female rather than by the male. Mr. Knight has
observed that individual cows, &c. however various the
[Seite 272] males, produce one sex rather than the other, so that he
has with tolerable certainty predicted the number of male
and female young; while nothing similar was ever ob-
servable in regard to bulls, rams, &c. Even the ex-
ternal appearance and the habits of animals and vegeta-
bles, he has found much more, and sometimes altogether,
influenced by the female. The quantity of pollen em-
ployed in the fecundation of female plants, he found of no
importance in this respect.*

(B) The form as well as the texture of the female is
more delicate: her surface has no muscular protuber-
ances, but is beautifully rounded; her legs therefore have
no calves, but, like the arms and fingers, they gently taper;
her feet and hands are small; her stature one sixth
shorter than that of the male; her neck longer. From
the smaller stature and the greater size of the abdominal
and lumbar regions, it follows that the middle point which
lies at the pubis in the male, is situated higher in the female.
Her abdomen is more prominent and rounded, and her
shoulders less forward and distant from the trunk. Her
thighs are more voluminous and distant from each other.

(C) The greater capacity of the female pelvis, which
contains the chief organs of generation and affords a
passage for the child, arises from the greater expansion
of the ossa ilei, the larger angle of the junction of the
ossa pubis, and the greater concavity and breadth of the
os sacrum: the os coccygis likewise is more slender and
moveable. The clavicles are less bent; the thorax more
projecting, whence deeper, although narrower and shorter;
the sternum shorter and broader; the cartilago ensi-
formus shorter; the two superior ribs flatter. Camper
remarks, that if the male and female forms are traced
[Seite 273] within two ellipses of equal dimensions, the male shoulders
will stand without and the pelvis within, while the female
shoulders will remain within and the pelvis without.*
The face and brain are absolutely smaller than in men, the
face likewise proportionally so; yet such is the relative
size of the cranium, that while in the male, the head,
including the teeth, is as 1 to 8 or 10, in the female it is
as 1 to 6, of the weight of the rest of the sceleton.

(D) An instance is related by Professor Roux of a
woman forty years of age who had one child and whose
breasts were well developed, having a strong and long
beard: the lobes of her ears were also covered with hair.
Hen birds have a far less beautiful and copious plumage
than cocks.

(E) Inferior to man in reasoning powers and corporeal
strength, woman possesses more sensibility of both body
and mind, more tenderness, affection, and compassion,
more of all that is endearing and capable of soothing
human woes, but less firmness of character, except indeed
where affection subsists; – although Varium et mutabile
semper foemina,
is a true character, yet nothing is too
irksome, too painful, or too perilous, for a mother, a wife,
or a mistress, to endure or attempt for the object of her
love.

(F) And beastly gluttons for the same reason are ge-
nerally men. A collection of cases of voraciousness will
be found in Professor Percy’s Memoire sur la Poliphagie.

SECT. XXXVI.
OF THE GENITAL FUNCTION IN MAN.

[Seite 274]

509. The genital fluid is produced in the two testicles,
which hang in the scrotum, by their spermatic chords,
through a ring called abdominal, or through, more pro-
perly, a fissure in the tendon of the external oblique
muscle of the abdomen. Besides abundant lymphatics,
three orders of vessels are found in the testes. (A)

The spermatic artery, which is, in proportion to the
fineness of its caliber, the longest artery, by far, in the
system, and usually conveys blood to the testicle imme-
diately from the aorta.

The ductus deferens, which carries to the vesiculae semi-
nales the semen separated from the arterial blood.

The pampiniform plexus of veins, which return to the
cava or renal vein the blood remaining after secretion (B).

510. The testes are not always suspended in the scro-
tum. In the very young male foetus, they are placed in
a far different situation, the nature and successive
changes of which were first accurately investigated by
Haller,* but have since been variously explained; and the
causes of this change of situation have given rise to
numerous controversies. I shall derive my account of
[Seite 275] this subject from the natural appearances which I have
preserved in a great number of small embryos, dissected
by me with this view.

511. On opening the lower part of the abdomen of a
young foetus, there appears in each groin, at the ring of
the oblique muscles, a very narrow opening in the peri-
tonaeum, leading downwards to a narrow passage which
perforates the ring and runs to a peculiar sac, extended
beyond the abdominal cavity towards the scrotum, inter-
woven with cellular fibres, and destined for the future re-
ception of the testicle.

512. At the posterior margin of this abdominal open-
ing, there is sent off another process of peritonaeum, run-
ning upwards, and appearing, in the young foetus, as
little more than a longitudinal fold, from the base of
which arises a small cylinder, or rather an inverted cone,
which terminates above in a globular sac, containing the
testis and epididymis, so that the testis, at first sight,
resembles a small berry resting on its stalk, and appears
hanging, like the liver or spleen, into the abdomen (399).

513. The vessels which afterwards constitute the sper-
matic chord, are seen running behind the very delicate
and pellucid peritonaeum; the spermatic artery and vein
descending along the sides of the spine, and the vas de-
ferens passing inwards in the loose cellular substance be-
hind the peritonaeum towards the neck of the bladder.
They enter the testis in the fold of peritonaeum just men-
tioned.

514. After about the middle period of pregnancy, the
testes gradually descend and approach the narrow passage
before spoken of (511), (the fold of peritonoeum becoming
at the same time doubled together with the cylinder) until
they lie directly over the opening of the passage.

[Seite 276]

515. The testis being now ready for its descent, the
opening which was hitherto small, becomes dilated, so as
to allow the organ to pass the abdominal ring and pas-
sage and descend into the bulbous sac (511); after this
occurrence, the opening soon becomes strongly closed
and even unites together, leaving scarcely any vestige of
itself in infancy.

516. In proportion to the slowness with which the testis
proceeded towards the opening, does its transit through
the abdominal passage appear rapid, and, as it were,
instantaneous. It is common to find the testis in mature
foetuses either lying over the peritonaeal opening, or,
having passed this, resting in the groin; but I once only
met with the right testis, in a twin foetus, at the very
time when it was adhering, and in a manner strangled, in
the middle of the passage, being just about to enter the sac;
in this instance, the left testis had passed the abdominal
canal and was already in the sac, and the abdominal
opening was perfectly closed.

517. This remarkable passage of the testis from the
abdomen through the groin, is limited to no period, but
would seem to occur generally about the last month of
pregnancy; not very rarely, however, the testicles are
found in the abdomen or the upper portion of the groin
at birth. For they have always another part of their
course to finish, after leaving the abdomen, viz. to de-
scend, together with their sac, from the groin into the
scrotum.

518. Repeated observation demonstrates this to be the
true course of the testicles. To assign the powers and
causes of its accomplishment is no easy matter. For I
am every day more convinced, that neither of the powers
to which it is usually ascribed, viz. the action of the
[Seite 277] cremaster or diaphragm, or the mere contractility of the
cellular membrane interwoven with tendinous fibres, which
adheres to the cylindrical process of peritonaeum (512)
and is called the Hunterian gubernaculum, is sufficient to
explain so singular a movement, and least of all to ex-
plain the transit of the testis through the passage so often
mentioned: but that the whole affords, if any thing does,
a striking illustration of a vita propria, without the pecu-
liar influence of which, so remarkable and unique a
course, similar to no other function of the system, cannot
even be scarcely imagined (C).

519. The coats of the testes, after their descent, are
conveniently divided into common and proper.

The common is the scrotum, consisting of the skin
having a very moderate substratum of fat and differing
from the rest of the integuments in this, – that it is con-
tinually changing its appearance, being sometimes lax and
pendulous, sometimes (especially during the venereal
orgasm and the application of cold) constricted and rigid,
and in the latter case, singularly marked by rugae and
furrows.

520. With respect to the coats proper to each testis,
the dartos lies immediately under the scrotum, and is en-
dowed with a peculiar and strong contractile power,
which deceived the celebrated Winslow, Haller, &c. into
the belief of the presence of muscularity (D).

521. Next to this, with the intervention however of
much soft cellular substance, are found three orders of
tunicae vaginales;* viz. an exterior common to the testis
[Seite 278] and spermatic chord, and to which the cremaster muscle
adheres by disjoined bundles of fibres; and two interior,
one proper to the chord, and one to the testis; the fundus
of the latter of which usually adheres to the common
coat, but is internally moistened, like the pericardium, by
a lubricating fluid (E).

522. The origin of these coats, – the subject of so much
controversy, may, I think, be readily explained, from the
circumstances already mentioned attending the descent of
the testis.

The common coat arises from the descending bulbous
sac or peritonaeal process (511).

The proper coat of the testis, from that production of
the peritonaeum which, ascending from the cylinder (512)
originally invests the testis.

The coat proper to the chord from that fold and short
cylinder of the peritonaeum in which the fold terminates
before it surrounds the testicle (F).

523. To the body of the testis* there adheres very
firmly, like the bark of a tree, a coat called albuginea,
through the combination of which with the internal part
of the vaginal coat, blood-vessels, penetrate into the pulpy
substance of the testis. This pulpy substance is entirely
composed of innumerable vessels, about a span in length
and convoluted into lobules, both conveying blood and
secreting semen,§ the latter of which is carried through
[Seite 279] the rete vasculosum of Haller* and the vasa efferentia
of de Graaf, to the apices of the cones of the epididymis.

524. The Epididymis, lying on the side of the testicle
and consisting of one vessel about thirty feet in length, is
less, and divided into about twenty glomerules or cones at
the part called its head, and is continued into the vas defe-
rens, at its lower part, which gradually becomes thicker§
and is denominated its tail.

525. Each vas deferens, ascending towards the neck of
the urinary bladder and converging towards the other
under the prostate gland, is then directed backwards and
dilated into the vesiculae seminales, in such a manner,
that the common mouth both of the vesicles and vasa
deferentia, opens into the urethra, behind the caput gal-
linaginis.

526. The vesiculae seminales, which adhere to the pos-
terior and inferior surface of the bladder, surrounded by
an abundance of fat, resemble two little intestines, va-
riously reflected, and branching into numerous blind ap-
pendices.

They consist of two coats, nearly similar to those of the
gall bladder; the one strong, and of the desription
usually termed nervous; the other interior, delicate,
abounding in cells, and divided into compartments by pro-
[Seite 280] minent ridges, like those found in the cervix of the gall
bladder.*

527. In these passages is slowly and sparingly secreted
and contained from the time of puberty, the semen, a very
remarkable and important fluid, of a milky yellowish
colour, of a peculiar odour, of the same viscidity as
mucus, and of great specific gravity, of greater indeed
than any other fluid of the body.

528. Semen has also this peculiarity, first observed by
Lewis Ham of Dantzic, in the year 1677,§ of being ani-
mated by an infinite number of small worms visible by the
microscope, of the kind denominated infusoria, and of dif-
ferent figures in different kinds of animals. In man, these
spermatic animalcules are oval and have very fine tails: they
are said to be found in prolific semen only, so that they are
in some degree an adventitious criterion of its prolific ma-
turity; I say adventitious, because I hope there is no
necessity, after so many weighty arguments, and obser-
vations,** at present to remark, that they have no fecunda-
[Seite 281] ting principle, nor much less are the germs of future
offspring (G).

529. The genital fluid gradually collected in the vesicles
is retained for subsequent excretion, and by its stay ex-
periences changes nearly similar to those of the bile in
the gall bladder; – becoming more inspissated and con-
centrated by the removal of its watery portion.*

530. As the whole of the testis and spermatic chord
abounds in lymphatic vessels which carry back to the
blood a fluid with a seminal impregnation and thus faci-
litate the secretion of semen in the manner before de-
scribed (477); so the vesiculae seminales are likewise fur-
nished with a similar set of vessels, which, by absorbing
the inert watery part, render the remaining semen more
powerful.

531. But I very much doubt whether the semen is ever
absorbed during health; still more that it ever passes
into the neighbouring veins; and most of all, that by
this absorption, if it does occur, unseasonable venereal
appetites are prevented; since, if we compare the phe-
nomena of animals procreating at particular periods, with
the constitution of those which are castrated, we must
conclude, that this absorption is rather the cause of un-
governable and almost rabid lust.

[Seite 282]

532. I conceive that this end is accomplished in a very
different mode, by a circumstance which occurs, as far as
I have been able to discover, in no animal but man, – by
nocturnal pollutions, which I regard among the natural*
excretions, intended to liberate the system from the
otherwise urgent superfluous semen, more or less fre-
quently, according to the variety of temperament and
constitution.

533. The semen is never discharged pure but mixed
with the prostate fluid, which is very much of the ap-
pearance of the white of egg, and has acquired its name
from the organ by which it is produced, an organ of some
size, of a singular and very compact texture, lying be-
tween the vesiculae seminales and bulb of the urethra, and
commonly denominated prostate gland. The passages
for the course of this fluid are not well known, unless
perhaps they communicate with the sinus of the seminal
caruncle, the middle of the orifice of which opens into
the urethra between the two mouths(525) of the seminal
vesicles.

534. The male urethra is the common emissary of three
different fluids, the urine, semen, and prostate fluid. It
is lined with mucus which proceeds from numerous
sinuses dispersed along the canal.§ We find it surrounded
[Seite 283] by a spongy texture, upon which lie two other spongy
bodies
* of much greater thickness, constituting the greater
part of the penis. The penis is terminated anteriorly by
the glans, a continuation of the spongy texture, usually
covered by a delicate and very moveable skin which is
destitute of fat, and, at the corona of the gland, forms the
preputium which moves over the gland as the eyelids do
over the eyeball. The internal duplicature of the prepu-
tium, changing its appearance, is reflected over the gland,
like the albuginea of the eye, and is beset at the corona
with many Littrian glands, similar to the Meibomian of
the eyelids, and secreting a peculiar smegma.

535. The virile organ thus constructed, enjoys the
power of erection; i.e. of becoming swollen and stiff,
and changing its situation, from the impetuous conges-
[Seite 284] tion and effusion* of blood into its corpora cavernosa
either by corporeal or mental stimulus, and of detu-
mifying and collapsing after the return of the blood (I).

536. When in a flaccid state, it is remarkably bent at
its origin from the neck of the bladder, and thus per-
fectly adapted for the discharge of urine, but quite unfit
for the emission of semen,§ because the origin of the
urethra then forms an acute angle with the openings of
the seminal vesicles.

537. When the penis swells from desire, the prostate
fluid generally flows first, and indeed is often discharged
pure, rarely together with the urine: its principal use is
to be emitted with the semen, either by its albuminous
lubricity correcting the viscidity of the former and pro-
moting its emission, or contributing something peculiar
to generation.

538. The emission of semen is excited by its abundance
in the vesicles and by sexual instinct: it is effected by the
violent tentigo which prevents the course of the urine, and,
as it were, throws the way open for the semen; by a kind
of spasmodic contraction of the vesiculae seminales, a con-
vulsion of the levatores ani** and of the acceleratores
[Seite 285] urinae, and by a short and less violent succussion of the
whole system, almost of an epileptic nature, and followed
by a great depression of the strength* (K).



NOTES.

(A) Instances of more than two testes are extremely
rare. Three, four, and even five, are said to have existed,
and Dionis in his Anatomy informs us, that he himself
once saw three in a person of rank, who assured him that
the greater part of his family were equally well pro-
vided. Haller quotes several authors for similar in-
stances. Unless such cases are related by an experienced
medical man from his own observation, they deserve no
credit, and even then must be regarded with suspicion,
if anatomical examination does not prove the additional
bodies to be analogous to testes no less in structure than
in form and situation. The late eccentric Dr. Mounsey,
who ordered that his body should either be dissected by
one of his friends or thrown into the Thames, was found
to have in his scrotum a small steatom, which during life
must have given the appearance of three testicles.

Writers who related these wonderful cases completely
disagree in their account of the powers of the individuals,
[Seite 286] some asserting them to be prodigious, others greatly below
those of ordinary men.

One testis is commonly larger than the other, and the
right spermatic chord being for the most part shorter
than the left, the right testis is generally the higher.

(B) The original situation of the testes accounts for the
circumstance of their blood vessels arising from the loins,
as Mr. Hunter remarked, for parts generally derive their
vessels from the nearest scource. The same applies to
their nerves. Hence too the right spermatic artery fre-
quently springs from the right renal as being nearer than
the aorta, and the left spermatic vein frequently pours
its blood into the left renal as being nearer than the in-
ferior vena cava.

The original situation of the testes accounts also for
the circumstance of the vas deferens arising from the
lower part of the epididymis and bending upwards; in
the foetus this is not the case, but it is the necessary con-
sequence of the subsequent change in the situation of the
testis.*

C. The descent of the testes into the scrotum must,
I apprehend, arise from the growth of their nerves
and vessels, and the direction afforded by the contrac-
tion of the gubernaculum; the growth of the former,
and therefore the whole process, is accounted for in the
minds of some by the contraction of the latter. Mr.
Hunter’s original account of the gubernaculum may
not be unacceptable. ‘“At this time of life, the testis
is connected in a very particular manner with the parietes
of the abdomen, at that place where in adult bodies, the
[Seite 287] spermatic vessels pass out, and likewise with the scrotum.
This connection is by means of a substance which runs
down from the lower end of the testis to the scrotum,
and which at present I shall call the ligament or guber-
naculum testis, because it connects the testis with the
scrotum, and seems to direct its course through the rings
of the abdominal muscles. It is of a pyramidal form;
its large bulbous head is upwards, and fixed to the lower
end of the testis and epididymis, and its lower and
slender extremity is lost in the cellular membrane of the
scrotum. The upper part of this ligament is within the
abdomen, before the psoas, reaching from the testis to
the groin, or to where the testicle is to pass out of the
abdomen; whence the ligament runs down into the scro-
tum, precisely in the same manner as the spermatic
vessels pass down in adult bodies, and is there lost. That
part of the ligamentum testis, which is within the abdo-
men, is covered by the peritonaeum all round, except at its
posterior part, which is contiguous to the psoas, and con-
nected with it by the reflected peritonaeum and by the cel-
lular membrane. It is hard to say what is the structure or
composition of this ligament: it is certainly vascular and
fibrous, and the fibres run in the direction of the ligament
itself, which is covered by the fibres of the cremaster or
musculus testis, placed immediately behind the peritonaeum.
This circumstance is not easily ascertained in the human
subject; but is very evident in others, more especially in
those whose testicles remain in the cavity of the abdomen
after the animal is full grown.”’*

(D) We know that the skin of every part relaxes by
heat and contracts by cold, although it is not muscular:
[Seite 288] in the cold fit of an ague, it is constricted throughout so
forcibly as to have acquired, during this state, the appel-
lation of Cutis Anserina. The scrotum being much
more lax than any other portion of the skin, experiences
these effects to the greatest extent. What is termed
dartos is merely thick cellular membrane.

(E) Another coat exterior to the rest, is described by
M. Roux, and termed Envelope fibreuse. It is an elon-
gated sac, large below to contain the testis and epidi-
dymis, and narrow above, affording a sheath to the chord.
It vanishes among the cellular membrane of the ring.*
M. Roux considers this coat as having been known to
Haller, from the following passage in Haller’s account of
the testicle. ‘“Ita fit ut interiores cavae duae sunt;
superior vasculis spermaticis circumjecta; inferior testi
propria.”’ But Haller continues thus, ‘“Ita saepe se habet,
ut etium aquae vis aut in partem testi propriam solam in-
tacta parte vasculosi funiculi, aut in istam solam, in-
tacta testis vagina, effundatur, neque flatus impulsus de
ea vaginali ad istam commeet.”’ He appears therefore
to describe merely the tunica vaginalis of the chord and
testis.

(F) The cremaster deserves a little attention. This
muscle arises from the superior anterior spinous process
of the ileum, from the transversalis abdominis, the in-
ternal surface of the Fallopian ligament and neighbour-
ing parts, and, passing through the ring, spreads upon
the chord, vanishing upon the beginning of the testi-
cle. Its office is evidently to support the testicle and
draw it upwards against the groin, during procrea-
[Seite 289] tion. In those animals, whose testes, instead of hanging
in the scrotum, lie in the perinaeum, the groin, or the
abdomen, this muscle is, as might be expected, much less
considerable.

It may here be mentioned, that the human testes do not
always descend into the scrotum, but occasionally remain,
one or both, in the groin or abdomen. Individuals so
circumstanced were called testicondi by the ancients. A
ridgil is a bull in which one only has descended. In
these instances the generative powers are not impaired;
a testicle which has not descended is prevented by the
pressure of the neighbouring parts from fully evolving
itself, but such persons, it is certain, ‘“militant non sine
gloria.
”’ The generative powers indeed are not impaired
by the removal of one testis: the Hottentots are said
always to cut away one from their sons, on arriving at
eight years of age, to render them lighter for running.
And we read in Varro, that if a bull is admitted to a cow
immediately after both testes are removed, impregnation
takes place, ‘“Exemptis testiculis, si statim admiseris,
concipere (vaccas)”’*. This at least is certain, that some
men have perfectly performed the act of copulation after
castration. In a case mentioned by Mr. Astley Cooper,
in his surgical lectures, the complete power remained some
time after the removal of both organs, but gradually di-
minished.

(G) According to Haller, Lewis Hamme, a young
German, discovered the seminal animalcules, and shewed
them to Leuwenhoeck; and the sagacious Dutchman,
[Seite 290] catching eagerly at the discovery, published an account of
them, illustrated by plates. Hartzoeker, ambitious of the
honour of the discovery, wrote upon the subject the fol-
lowing year, and asserted that he had seen the animal-
cules three years before they were observed by Hamme.
The subject, being the very summit of filthiness, excited the
earnest attention of all Europe. Physiologists, Naturalists,
Popish Priests, Painters, Opticians, and Booksellers, all
eagerly joined in the pursuit of the seminal animalcules,
and the lascivious Charles the Second, of England, com-
manded them to be presented to him swimming and frisking
in their native fluid. Some of the curious could not find
them. Others not only found them, but ascertained their
length to be the 3/100000 part of an inch, their bulk such
as to admit the existence of 216,000 in a sphere whose
diameter was the breadth of a hair, and their rate of tra-
velling to be nine inches in an hour. They saw them too
in the semen of all animals, and, what is remarkable, of
nearly the same size and shape in the semen of the
largest and of the smallest, in the semen of the sprat
and of the whale; they could distinguish the male
from the female; in the semen of a ram, they beheld
them moving forwards in a troop, with great gravity,
like a flock of sheep; and in the human semen, Da-
lenpatius actually saw one indignantly burst its wormy
skin, and issue forth a perfectly formed human being.
The little creatures would swim in shoals towards a
given point, turn back, separate, meet again, move on
singly, jump out, and dive in again, spin round, and per-
form various other feats, proving themselves, if not the
most delicate, at least the most droll, beings that ever
engaged the attention of philosophers. Their strength of
constitution being an important object of enquiry, they
[Seite 291] gave proofs of their vigour, not only by surviving their
rough passage through the urethra three, four, and seven
days, but by impregnating a female at the end of this time,
and, on being removed from her, by impregnating even a
second. Sure never was so much folly and bestiality before
committed under the name of philosophy.

A. Kauw Boerhaave, Maupertuis, Lieutand, Ledermul-
ler, Monro Secundus, Nicolas, Haller, and indeed nearly
all the philosophers of Europe, were satisfied of the exist-
ence of the animalcules. Buffon and his followers, preju-
diced in favour of an hypothesis, although they did not
deny that the semen contained innumerable rapidly moving
particles, contended that these were not animalcules, but
organic particles; and Linnaeus imagined them to be inert
molecules, thrown into agitation by the warmth of the
fluid. Their reality, however, might be regarded as
established. But finally to determine the question, and
accurately to ascertain every circumstance relating to them,
the celebrated Spallanzani began a long course of obser-
vations and experiments about the middle of the last
century, unbiassed in favour of any opinion, and endea-
vouring to forget entirely all that had been written upon
the subject. The human semen he procured from bodies
immediately after death, and that of animals either after
death or during life.

He found in the former innumerable animalcules, with
an oval body, and a tail, or appendix, tapering to a point.
This appendix, by moving from side to side, propelled
them forwards. They were in constant motion in every
direction. In about twenty-three minutes their move-
ments became more languid, and in two or three hours
they generally died, sinking to the bottom of the fluid,
with their appendices extended. The duration of their
[Seite 292] life, however, depended much upon the temperature of
the weather; at 2 below 0 (Reaumur) they died in 3/4 of
an hour; while at 7° they lived two hours, and at 12 1/2, three
hours and three quarters. If the cold was not too intense,
they recovered upon the temperature being raised; when
only 3 or 4 below 0, they recovered after a lethargy of four-
teen hours and upwards: and, according to the less intensity
of the cold, they might be made to pass from the torpid to
the active state more frequently. They were destroyed by
river, ice, snow, and rain-water; by sulphur, tobacco, cam-
phor, and electricity. Even the air was injurious to them;
in close vessels, their life was prolonged to some days, and
their movements were not constant and hurried. They
were of various sizes, and perfectly distinct from all species
of animalcules found in vegetable infusions, &c. The se-
minal animalcules of different kinds of animals had generally
each some peculiarity. In short, Spallanzani completely
confirmed the chief observations of Leuwenhoeck, and
satisfactorily explained the sources of the inaccuracies of
other enquirers.*

Although these beings are most numerous in the semen,
he detected them occasionally in other fluids; – in the
mesenteric blood of female frogs and salamanders, and in
the blood of a tadpole and a calf.

It were to be wished that another Spallanzani would pro-
secute these enquiries.

According to Vauquelin’s analysis of the semen, 100 parts
contain,

[Seite 293]
Of water 9.0
Mucilage 6
Phosphate of lime 3
Soda 1

In some days it putrifies, and becomes covered with the
byssus septica.*

(H) Mr. Hunter’s arguments are very forcible. 1.
‘“The semen, first discharged from the living body, is of
a blueish white colour, in consistence like cream, and
similar to what is found in the vasa deferentia after
death; while that which follows is somewhat like the
common mucus of the nose, but less viscid. The semen
becomes more fluid upon exposure to the air, particularly
that first thrown out; which is the very reverse of what
happens to secretions in general. The smell of the semen
is mawkish and unpleasant, exactly resembling that of the
farina of a Spanish chesnut; and to the taste, though at
first insipid, it has so much pungency, as, after some little
time, to stimulate and excite a degree of heat in the
mouth. But the fluid contained in these vesiculae, in a
dead body, is of a brownish colour, and often varies in
consistence in different parts of the bag, as if not well
mixed. Its smell does not resemble that of the semen,
neither does it become more fluid by being exposed to
the air.”’ On opening two men immediately after death,
the contents of the vesiculae were of a lighter colour than
he usually found them in persons who had been some
time dead, and, in one of the instances, so fluid as to run
out upon cutting the vesiculae, but they were similar to
the semen neither in colour nor smell. An examination of
the vesiculae of the horse, boar, rat, beaver, and guinea-
pig, afforded the same results. In the last animal, the
[Seite 294] contents near the fundus of the vesiculae were viscid, and
gradually firmer, till, near the opening into the urethra,
they were as solid as common cheese, and no such sub-
stance could be detected in the vagina of the female after
her union with the male. 2. During lasciviousness, the tes-
ticles swell, and they become painful, if the semen is not dis-
charged; in coition, it may be added, they are drawn for-
cibly by the cremaster against the pubis, as if to assist the
discharge of their contents at the period of emission. 3.
In the old and debilitated, the vesiculae are as full as in
the young and vigorous. 4. Nay, in four men, who had
each lost a testicle, the vesicula on one side was equally
full as on the other, although they had survived the
operation a considerble length of time. The same was
discovered in two cases, where, by mal-formation, one testi-
cle had no communication with the corresponding vesicle.
In the gelding and the stallion their contents are similar,
and nearly equal in quantity. The vas deferens has no
communication in some animals with the vesiculae, and in
others, as the horse, where a communication does exist,
the common duct is not of sufficient length to permit the
regurgitation of the semen into the vesiculae. 5. Some
animals, especially among the carnivora, have no vesiculae
seminales, yet in their copulation they differ not from
those which have. M. Richerand, indeed, asserts, that
animals destitute of these organs are longer in coition
than others, from having no reservoir for an accumulation
of semen.* But he is mistaken. For, on inspecting Cu-
vier’s account of animals without and with vesiculae, no
connection whatever appears between their presence or
absence and the length of copulation.

In opposition to these arguments I have only to remark,
[Seite 295] that a fluid, gently propelled along the vas deferens, does
not pass into the urethra, but regurgitates into the vesi-
culae,* and that in a case of seminal weakness, which I
lately saw, the act of straining at the water-closet instantly
discharged from the urethra, without the least sensation,
a large quantity of a fluid, which the patient, who was of
course unprejudiced in favour of any opinion, assured me
was exactly similar in colour, consistence, and odour, to
that of a nocturnal emission. The compression could
not have sqeezed this fluid from the testes. If a partizan
of Mr. Hunter should say that the extremities of the vasa
deferentia afforded it, I reply, that Mr. Hunter found them
full of the same kind of fluid as the vesiculae.

(I) Accumulation of blood, it is supposed, may be pro-
duced in three ways. 1. By an impediment to its return:
but there is no reason whatever, to ascribe the ordinary
erection to compression. 2. By an increased flow of
blood to a part, so that the vessels receive it faster than
they convey it away. Here the vessels of the part, in
which the accumulation exists, are said by some to act
more violently than usual; by others, the neighbouring
larger vessels which supply these: their frequency of
action, however, is not increased, but always remains
correspondent with that of the heart. Were the vessels
of the part itself to act more violently than usual, that is
to say, to contract to a smaller and relax to a greater di-
mension than usual, more blood would indeed subsist in
them during their relaxation, but less than usual would
subsist in them during their contraction, and there could
be no accumulation, no inflammation. If the neighbour-
ing large vessels act more violently than usual, they may
be conceived to produce an accumulation of blood and a
[Seite 296] distension of the smaller vessels. 3. If the vessels of any
part become dilated, and do not contract in proportion,
this circumstance will be sufficient to produce an accu-
mulation, without any necessity for supposing an increased
action of the neighbouring larger vessels. This explains
inflammation: and in Bichat’s Anatomie Descriptive, this
explanation is given of erection. The corpora cavernosa,
which always contain florid blood, spontaneously dilate,
and accumulation ensues. For this purpose it is not
necessary that they should be muscular, but Mr. Hunter
asserts their muscularity: in a horse, he found them mus-
cular to the eye, and they contracted upon being stimu-
lated.

As to the final cause of erection, the organ, by ac-
quiring increased bulk, firmness, and sensibility, becomes
adapted for both affording and experiencing to the utmost
extent the effects of friction, both as exciting pleasure and
as stimulating the secreting vessels; the urethra, by be-
coming longer and narrower, renders the emission more
forcible.

(K) The discharge of semen resembles the discharge of
fluids from all glands. It is excited by the abundance of
the fluid, by mental stimulus, or by mechanical irritation of
the extremity of the excretory duct, for in such a point of
view must be regarded the friction of the glans penis in
copulation. The fluid is accumulated in the bulb of the
urethra, for it must be accumulated somewhere to be
emitted so copiously, and no other use can be assigned to
the bulb; and if the vesiculae do not receive it, no other
part but the bulb can; and besides, it is upon the bulb
that the muscular contraction of the venereal paroxysm
first acts. ‘“The semen, acting as a stimulus to the cavity
of the bulb of the urethra, the muscles of that part of the
canal are thrown into action, the fibres nearest the bladder
[Seite 297] probably act first, and those more forward in quick succes-
sion, and the semen is projected with some force. The blood
in the bulb of the urethra is by the same action squeezed
forward, but, requiring a greater impulse to propel it, is ra-
ther later than the semen, on which it presses from behind;
the corpus spongiosum, being full of blood, acts almost as
quick as undulation, in which it is assisted by the corres-
ponding constriction of the urethra, and the semen is hurried
along with a considerable velocity.”’*

(L) If Gall is right, in placing the seat of sexual desire
in the head, this kind of erection may be explained by
supposing the irritation, arising in the cerebellum from the
great accumulation of its blood, to produce a correspondent
irritation in the organs of generation: thus the epileptic
paroxysm is not unfrequently accompanied by an emis-
sion. Nocturnal emissions occur most frequently after a
person has been long in bed and supine – the cerebellum the
lowest part.

(M) Zeno’s practice was conformable to his principles.
He embraced his wife but once in his life, and then out of
mere politeness.

Epicurus, Democritus, &c. were nearly of the same
opinion with Zeno; and the Athletae, that their strength
might be unimpaired, never married. The rabbies, in
their anxiety to preserve their nation, are said to have or-
dered, with the view of preventing the loss of vigour, that a
peasant should indulge but once a week, a merchant but
once a month, a sailor but twice a year, and a studious man
but once in two years.

SECT. XXXVII.
OF THE GENITAL FUNCTION OF WOMEN IN GENERAL.

[Seite 298]

539. As the male organs are fitted for affording, so the
female organs are fitted for receiving, and are correspond-
ently opposite to the former. In some parts, the organs
of each sex are very analogous to each other in structure.
Thus the clitoris, lying under the pubis in the superior com-
missure of the labia, agrees in many respects with the
penis of the male, although distinct from the urethra, and
imperforate and extremely small in well-formed women.
It is recorded to have been, in some adult females, of as
comparatively large size as we stated it usually to be in the
foetus (492), and these instances probably gave rise to
most of the idle stories of hermaphrodites.* Like the
penis, it has its corpora cavernosa, is capable of erection,
covered with a prepuce, and secretes a smegma not unlike
the Littrian (525).

[Seite 299]

540. From the clitoris the nymphae descend, also oc-
casionally of great size,* the source of other idle tales,
and, like the clitoris, possessing a high degree of sensi-
bility. They appear in some measure to direct the stream
of urine, because the opening of the urethra, which is
very short in females, and frequently ciliated, as it were,
with small papillary folds, lies under their commence-
ment.

541. Under the termination of the urethra lies the open-
ing of the vagina,
surrounded with various kinds of cryp-
tae; v.c. the lacunae urethericae of De Graaf,§ and the
orifices of the prostates, as they are improperly termed,
of Casp. Bartholin,ǁ which secrete an unctuous mucus.

[Seite 300]

542. Across the opening of the vagina, the Hymen* is
extended, – a membrane generally circular, found, as far
as I know, in the human subject alone, and of no physi-
cal use hitherto discovered.

The remains of the lacerated hymen become the carun-
culae myrtiformes,
which are of no regular number, and
are infallible signs of the loss of virginity. (B)

543. The vagina, ascending between the urinary blad-
der and rectum, consists of a very vascular cellular paren-
chyma; is surrounded inferiorly by the constrictor cunni,
and lined internally with a very soft coat, which is marked
by two columns of rugae, an interior and posterior,§ pour-
ing forth a mucus into its cavity.

544. Upon the superior part of the vagina rests the
uterus, suspended on either side by its broad ligaments.
Its cylindrical cervixǁ is embraced by the vagina, and
perforated by a narrow canal, which, like the vagina, is
marked by rugae, denominated the arbor vitae, and is
generally lined with a viscid mucus at each extremity, but
particularly at the superior.

545. The substance of the uterus is peculiar, a very
dense and compact parenchyma, abounding in blood-
[Seite 301] vessels, which run in a curious serpentine direction* and
are destitute of valves. It has also a supply of lympha-
tics; and a great number of nerves, whence its remarkable
sympathy with other parts.

546. The uterus is covered externally with perito-
naeum; its internal cavity is small, and lined, especially
at the fundus, with a soft and very delicate spongy mem-
brane, which is composed, according to some, (92) of co-
lourless arteries and veins, (92) and,§ according to others,
of lymphatics.ǁ

547. With respect to its muscularity, asserted by some
and denied by others**, I may remark, that I have never
yet discovered a true muscular fibre in any human uterus
which I have ever dissected, whether impregnated or un-
impregnated, recent or prepared; but it must be allowed,
that the fibres, termed by some muscular, have qualities
very different from any others observable in the system.
I am daily more convinced that the uterus has no true
irritability, (301) but a vita propria, (42) correspondent
with the peculiar motions and functions of the uterus,
[Seite 302] which are not referrible to any properties common to the
similar parts, (39–41) and which appeared to the ancient
physicians and philosophers so peculiar, that the uterus
was by them denominated an animal within an ani-
mal.* (C)

548. From the angles of the roof or fundus of the ute-
rus arise on each side the Fallopian tubes, narrow and
tortuous canals, running in the upper part of the dupli-
cature of the broad ligaments, similar in texture to the
vagina, but internally destitute of rugae, and lined by a
very soft and delicate spongy substance.

549. The extremity which opens into the abdomen is not
only larger than that which opens into the uterus, but is
surrounded by laciniated or digitated fimbriae, singular
and elegant in structure, which are probably of great im-
portance in conception, since they appear to become tur-
gid as well as the tubes themselves, during the venereal
oestrum, and to embrace the ovaria over which they lie.

550. The ovaria, or, as they were termed previously
to the time of Steno, the female testes, are composed of
a tough and almost tendinous covering, and a dense and
closely compacted cellular substance, which contains in
each ovarium about fifteen ovula, called Graafian, viz.
vesicles, or rather drops of albuminous yellow serum,
which coagulates like white of eggs, if the recent ovarium
is plunged into boiling water.

[Seite 303]

551. Such an albuminous drop appears to be what the
female contributes in the business of conception, and it is
probable, that, during the adult state, these drops become
mature in succession, so that they one by one force their
way, and finally burst the covering of the ovarium, and
are received by the abdominal extremity of the Fallopian
tube.

552. Besides the albuminous drop which escapes from
the ovarium, another fluid, improperly female semen
by the ancients, is poured forth during the venereal oes-
trum. Its nature, source, and quantity, are enveloped in
no less mystery than its office.*



NOTES.

(A) The Hottentot peculiarity is a prolongation of the
labia.

(B) The various size of the opening of the vagina in
virgins and women, and the various firmness of the or-
gans, must ever leave those in uncertainty, who can on
their marriage indulge in sensual doubts. We read in
Hume, that Henry the Eighth, who certainly had his share
of experience, boasted his discrimination; but an eastern
monarch, whose experience was infinitely greater, confess-
ed his ignorance.

The lovers of Italian literature know how strictly natu-
ral is every description of Boccacio’s, and will recollect
[Seite 304] his story of the daughter of the Sultan of Babylon, ‘“Essa
che con otto nomini forse dicemilia volte giacuta era, a
lato a lui (al Re del Garbo) si conciò, per pulcella, e fece
gli credere, che cosi fosse.”’*

C. The muscularity of the uterus is allowed by Mal-
pighi, Morgagni, Mery, Littre, Astruc, Ruysh, Monro,
Vieussens, Haller, &c.

Mr. Charles Bell has a paper in the fourth volume of
the Medical and Surgical Society, which it is necessary
to quote freely, in order to give an accurate description
of the muscular structure of this organ.

‘“The muscularity of the uterus is proved by direct ocu-
lar demonstration of the fibres in dissection, by the thick-
ness of the fibres corresponding with their degree of con-
traction, by the visible action of the human uterus during
life, by the resemblance of the laws of its contraction, (as
felt and as perceived in its consequences) to those which
govern the contraction of other hollow viscera, and, lastly,
by the vermicular and intestinal motions of the uterus, as
seen in experiments upon brutes.”’

‘“The most curious and obviously useful part of the
muscular substance of the uterus has been overlooked;
I mean the muscular layer of fibres which covers the up-
per segment of the gravid uterus. The fibres arise from
the round ligaments, and regularly diverging, spread over
the fundus, until they unite and form the outermost stra-
tum of the muscular substance of the uterus.”’

‘“The substance of the gravid uterus is powerfully and
distinctly muscular; but the course of the fibres is here
less easily described than might be imagined. Towards
the fundus the circular fibres prevail; towards the orifice
the longitudinal fibres are the most apparent; and, on the
[Seite 305] whole, the most general course of the fibres is from the
fundus towards the orifice. This prevalence of longitu-
dinal fibres is undoubtedly a provision for diminishing the
length of the uterus, and for drawing the fundus towards
the orifice. At the same time these longitudinal fibres
must dilate the orifice, and draw the lower part of the
womb over the head of the child.”’

‘“In making sections of the uterus while it retained its
natural muscular contraction, I have been much struck
in observing how entirely the blood vessels were closed
and invisible, and how open and distinct the mouths of
the cut blood vessels became, when the same portions of
the substance of the uterus were distended and relaxed.”
“A very principal effect of the muscular action of the
womb is the constringing of the numerous vessels which
supply the placenta, and which must be ruptured when
the placenta is separated from the womb.”’

‘“Upon inventing the uterus and brushing off the deci-
dua, the muscular structure is very distinctly seen. The
inner surface of the fundus consists of two sets of fibres,
running in concentric circles round the orifices of the Fal-
lopian tubes. These circles at their circumference unite
and mingle, making an intricate tissue. Ruysch, I am
inclined to believe, saw the circular fibres of one side
only,* and not adverting to the circumstance of the Fal-
lopian tubes opening in the centre of these fibres, which
would have proved their lateral position, he described the
muscle as seated in the centre of the fundus uteri. This
structure of the inner surface of the fundus of the ute-
[Seite 306] rus is still adapted to the explanation of Ruysch, which
was, that this produced contraction and corrugation of
the surface of the uterus, which the placenta not partak-
ing of, the cohesion of the surface was necessarily broken.”’

‘“Further, I have observed a set of fibres of the inner
surface of the uterus which are not described. They com-
mence at the centre of the last described muscle, and hav-
ing a course at first in some degree vorticose, they de-
scend in a broad irregular band towards the orifice of the
uterus. These fibres co-operating with the external
muscle of the uterus, and with the general mass of fibres
in the substance of it, must tend to draw down the fun-
dus and lower segment of the uterus over the child’s head.”’

‘“I have not succeeded in discovering circular fibres in
the os tunicae corresponding in place and office with the
sphincter of other hollow viscera, and I am therefore in-
clined to believe, that, in the relaxing and opening of the
orifice of the uterus, the change does not result from a re-
laxation of muscular fibres surrounding the orifice. In-
deed, it is not unreasonable to conceive, that the contents
of the uterus are to be retained during the nine months of
gestation by the action of a sphincter muscle. The loosen-
ing of the orifice, and that softening and relaxation which
precede labour, are quite unlike the yielding of a muscular
ring.”’

SECT. XXXVIII.
OF THE MENSTRUA.

[Seite 307]

553. An important, and indeed the most frequent
function of the uterus, is to afford a menstrual fluid during
about thirty years, – a law imposed upon no other species of
animal.* – Woman, in the words of Pliny, is the only
menstruating animal. – The females of no nation, hitherto
explored, are exempt from this law, since it is among
[Seite 308] the requisites in the female sex, for the propagation of
the species.

554. The commencement of this function usually occurs
about the fifteenth year, preceded by symptoms of ple-
thora, by a sense of heaviness in the chest, and of tension
in the loins, by lassitude of the limbs, &c. From the first
of these symptoms, a reddish fluid generally flows from
the genitals, becoming by degrees of a more bloodv co-
lour, and at length completely so. This has a peculiar
odour, coagulates but imperfectly, and differs also in other
respects from blood. It continues to flow slowly for some
days, and the unpleasant symptoms above described in
the mean time cease.

555. This red discharge returns after this period about
every four weeks, and continues about six days, during
which time a healthy woman is supposed to lose, perhaps,
from five ounces to half a pound of blood.

556. This action is usually discontinued during preg-
nancy or lactation. It entirely ceases after existing about
thirty years; that is, in our climate, about the forty-fifth
year.

557. By some, the vagina, by others, and with more
probability, the uterus, is considered the source of this dis-
charge. Arguments adduced against the latter opinion,
from the examples of women menstruating although preg-
nant, or having the uterus imperforate or prolapsed, prove
only the extraordinary compensating powers of nature,
who employs new ways, when the customary are im-
[Seite 309] peded. On the other hand, the dissection of many women
who have died during menstruation has discovered the
cavity of the uterus bedewed with the catamenia.* I say
nothing of the a priori argument, – that the purpose of
menstruation is probably to render the womb fit for preg-
nancy, and for nourishing the foetus. For the same
reasons, the arteries, rather than the veins, appear to be the
source of the discharge.

558. The investigation of the causes of the periodical
return of this hemorrhage is so difficult, that we can obtain
nothing beyond probability, and shall not dare to offer any
thing merely conjectural.§

The proximate cause is supposed to be a localǁ plethoric
[Seite 310] congestion; – an opinion, with which the symptoms preced-
ing menstruation, and the abundance and nature of the
uterine vessels, agree very well.

Among the remote causes may be enumerated the erect
posture peculiar to the human race, the peculiar paren-
chyma of the uterus, and its vita propria.

It will be better to confess our ignorance of the cause of
its periodical return, than to indulge in vain hypotheses:
all the periodical phenomena of health and disease, which
continue more than twenty four hours,
are among the mys-
teries of animal nature.

SECT. XXXIX.
OF CONCEPTION AND PREGNANCY.

[Seite 311]

559. We now come to the functions for which the geni-
tal organs are given us – to conception, and the propagation
of the species – in treating which, we shall first merely de-
scribe the phenomena which are observed in that admirable
and truly divine process, and afterwards investigate the
powers by which they are produced.

560. In the first place, it is worthy of remark, that the
human race, unlike most animals, does not copulate at cer-
tain periods of the year,* but that, with it, every season is
equally favourable to the flame of love.

561. When a woman admits the embraces of a man,
and both burn with that animal instinct which is superior
to all others in universality and violence, the uterus, I
conceive, swelling with a kind of inflammatory orgasm,(A)
[Seite 312] and animated by its vita propria (547), draws in, as it
were, the semen ejaculated by the male,* and appears to
pour forth a fluid of its own against it (552); the tubes
become rigid, and their fimbriae embrace the ovaria, in
one of which a ripe Graafian vesicle bursts like an
abscess, and its albuminous drop of fluid, being absorbed
by the abdominal opening of the tube, is conveyed to the
womb.

562. After the escape of this drop from the ovarium, the
lips of the womb are closed by an external cicatrix, and the
remaining vascular membrane is converted into a corpus lu-
teum.
This is at first hollow, and full, as I think, of a plas-
tic lymph, which in progress of time becomes a fleshy
nucleus, surrounded with a thick cortex, remarkably vas-
cular.§ (A)

[Seite 313]

563. After impregnation, the canal which runs along
the cervix of the uterus is thoroughly closed, especially
towards its superior or internal orifice (544), so that super-
foetation, properly so called,* cannot naturally take place.
There are scarcely any constant and infallible signs, by
which the woman herself can be very certain of the changes
which occur within during conception.

564. The internal surface of the uterus becomes lined
with plastic, and, as it were, inflammatory lymph (15),
which forms the tunica caduca, or decidua of Hunter.
[Seite 314] This is said to consist of two laminae, the crassa investing
the uterus, excepting at the orifices of the tubes and of the
canal of the cervix;* the other being, after the ovulum
begins to be formed and to take root in the decidua, con-
tinued over the rest of the ovum, as the peritonaeum is
continued over the abdominal viscera, is denominated the
caduca reflexa.

565. The ovulum is produced before the embryo which
it is intended to receive, but scarcely begins to be formed
before the second week from conception. Previously to
this period, I very much doubt whether any vestige of
human conception has ever been visible.

566. This ovulum consists, besides the external acces-
sary covering afforded by the caduca of Hunter, of two
proper velamenta or membranes.

Of an exterior, – the chorion§ of the moderns; the ex-
ternal surface of which is, from the first, nearly covered
with inexpressibly beautiful knotty flocculi; whence it
has been called the flocculent, leafy, or mossy, chorion.
By means of these flocculi, which are the rudiments of the
foetal portion of the future placenta, the ovulum takes root,
as it were, in the uterine decidua (564).

[Seite 315]

Of an interior, styled amnion, possessing no blood ves-
sels (5), delicate, but remarkably tough.

567. These two proper membranes of the ovulum differ
very much from each other in size the first week after
the formation of the ovum; the chorion appears a large
bladder, to which the amnion, like a much smaller blad-
der, adheres in that part only which nearly corresponds
with the centre of the external flocculent surface of the
chorion.

The remaining space between the chorion and amnion
is filled by a clear water, which may be called the liquor
chorii,
of doubtful origin and short duration.

For since the amnion increases more rapidly than the
chorion, and approximates to the latter even during the
first months after conception,* in proportion to its approxi-
mation must this fluid necessarily be absorbed.

568. The internal membrane of the ovum is filled, from
its first formation (565) to the last moment of pregnancy,
with the liquor amnii, an aqueous fluid, of a yellowish
colour, nearly inodorous, of a bland and scarcely saltish
taste, commonly thought nourishing, and compared to
albumen, from which, however, more accurate investiga-
tion proves it to differ considerably.

Its source is doubtful, and cannot be referred to the
[Seite 316] foetus or umbilical chord, since it exists in abortive ovula
containing neither.

Its quantity is inversely as the size of the foetus.
Hence we may conjecture, that its use is rather to defend
the foetus while nearly gelatinous and most liable to suf-
fer from external injuries, than to afford nourishment.
That the portion of the fluid which occasionally, although
rarely, and therefore not naturally, enters the stomach of
the foetus, is not destined to nourish it, is evident from
the nature of this fluid, and from the state of the chylo-
poietic system of the foetus: to omit arguments deduced
from acephalous foetuses, &c.*

569. The embryo, which swims in this fluid, suspended
by the umbilical chord, like fruit by its stalk, begins to
be formed from about the third week after conception:
at first it appears to be of a rather globular shape, resem-
bling a little bean or kidney, from which the rudiments
of the extremities grow, and the face is at length formed,
and s. p.

[Seite 317]

570. By nature, woman is uniparous, conceiving but one
foetus. Frequently, however, she produces twins, the pro-
portion of which to single births, Süssmilch estimates as 1 to
70.* In these cases, each child has usually its own amnion,
but there is a common chorion.

571. The medium of connection between the mother and
the child are, the umbilical chord, and the placenta into
which it is distributed.

572. The umbilical chord, which appears coeval with
the embryo, varies exceedingly in length and thickness,
in the place of its insertion into the placenta, in its va-
ricose knots, &c. It generally consists of three blood
vessels twisted spirally together, viz. a vein running to
the liver of the foetus, and two arteries arising from its
internal iliacs or hypogastrics. They are separated from
each other by cellular septa of various directions, and are
[Seite 318] throughout narrowed internally by nodules, or the quasi-
valves
of Hoboken.*

They are collected into a chord by means of a cellular
membrane, which is full of a singular very limpid fluid
called Whartonian, resembling gelatine in appearance,
and is surrounded externally by a continuation of the am-
nion.

573. At the part of the chord which is united to the
foetus, there runs the urachus, which arises from the fun-
dus of the urinary bladder, and lies between the two um-
bilical arteries. In the human subject, it is pervious but
for a very short distance, and, indeed, soon disappears
altogether. In other mammalia it leads to the allantoid,
which is universally acknowledged to be absent in the hu-
man foetus. For I think that the problematical vesicula
umbilicalis,
found in human ovula between the chorion
and amnion,§ is not analogous to the allantoid,ǁ but to
the tunica erythroides, found in the ova of some mamma-
lia, and to the vitellary sac of the incubated egg. It
is found in healthy human ovula, the second or third
[Seite 319] month from conception, too frequently and of too constant
an appearance to be regarded as accidental, morbid, or
monstrous.*

574. The blood vessels of the chord pass to the pla-
centa, of whose origin from the flocculent surface of the
chorion united to the decidua crassa, we formerly spoke.
Hence we discover how the substance of the placenta is
double – the uterine portion derived from the decidua and
forming a spongy parenchyma: the foetal arising from the
umbilical vessels distributed on the chorion. The increase
of the ovulum is irregular, so that the smooth part of the
chorion grows more rapidly than the flocculent: conse-
quently, the size of the placenta bears a greater propor-
[Seite 320] tion to that of the ovum, the shorter the period which has
elapsed since conception, and a smaller, as the period of
labour approaches.

As pregnancy advances, its texture becomes more com-
pact, sulcated, and lobular on its uterine surface, and
more smooth on its interior surface, which is covered by
the amnion. It varies greatly in size, thickness, figure,
and situation, or place of attachment to the uterus; ge-
nerally it adheres to the fundus; it is destitute of sensibili-
ty and true irritability.

575. Although all agree that the placenta is the chief in-
strument in the nourishment of the foetus, the true mode of
its operation, and its mutual relation to the uterus and foetus,
have given rise to great controversies in modern times.
After all, the truth appears to be this, – that no anastomosis
exists between the blood vessels of the uterus and of the
chord: but that the oxygenized blood, which proceeds from
the uterus to that portion of the placenta which was origi-
nally the decidua crassa, is absorbed by the extreme radi-
cles of the umbilical vein distributed upon the flocculent
chorion, and carried to the great venous trunk of the chord;
the carbonized blood returning from the foetus, through the
umbilical arteries, being poured in the same manner into
the substance of the placenta, is absorbed by the venous
radicles of the uterine portion of the placenta, and returned
to the uterus.

This account is supported by very careful but fruitless
attempts to inject the umbilical by means of the uterine
vessels, and the uterine by means of the umbilical; or to
tinge the bones of the foetus with red, by giving madder
to the mother during pregnancy. It is also confirmed by
the difference observable between the blood of the mother
and foetus. (D)

[Seite 321]

576. During the progress of pregnancy, while the foetus
and secundines are increasing, the uterus of course under-
goes important changes, not only in its size, but situation,
figure, and especially in its texture, which is considerably
changed both in regard to its blood vessels and the inter-
vening parenchyma, from the constant and great congestion
of fluids which occurs.

In proportion as the uterus increases, the blood vessels,
from being tortuous and narrow, become more straight* and
capacious, and the veins, near the termination of pregnancy,
acquire so great a bulk as to have been taken for sinuses
by some anatomists.

The parenchyma becomes gradually more thin and lax,
especially in the part nearest the ovum, so that although the
gravid uterus is very thick, particularly at its fundus, and in
a living and healthy woman is turgid with blood and replete
with vital energy, nevertheless it is soft, and its general na-
ture, especially after death, when, as Arantius long since
remarked, it almost appears lamellated in advanced preg-
nancy,§ extremely different from the firm and compact sub-
stance of the unimpregnated uterus.

577. The remaining important changesǁ of the gravid
uterus, as well as those still more remarkable which oc-
cur to the ovum and foetus, we shall briefly relate in the
[Seite 322] order of the ten lunar months, according to which pregnan-
cy is at present very conveniently calculated.

578. As the uterus immediately after impregnation al-
ways becomes turgid, (561) so, increasing from that pe-
riod in bulk and weight, it descends into the upper part
of the vagina, still retaining its former figure during the
first three months, except that, perhaps, its fundus becomes
a little more convex, and its anterior portion somewhat
recedes from the posterior, and that its cavity, before ex-
tremely small and nearly triangular, becoming expanded
by the fluids of the ovum, accommodates itself to their sub-
globular form.

The ovum itself, which, about the termination of the first
month, is of the size of a pigeon’s egg, and possesses both de-
cidua separate from each other, and the minute amnion se-
parate from the larger chorion, commonly attains, near the
end of the third month, the size of a goose’s egg; the de-
cidua reflexa then closely approaches to the crassa, and the
amnion to the chorion; the former is filled with the fluid
which bears its name, and defends from the pressure of the
womb the tender embryo, now very small in proportion to
it, scarcely, indeed, equal to the size of a young mouse, and
variable and dependent* in situation.

579. From the fourth month, the uterus becomes more
oval or subglobular, and its neck gradually softening,
shortening, and almost disappearing, or rather distending
laterally, it tends upwards, and begins to rise to the supe-
rior part of the pelvis. At the same time the tubes ascend
with the convex fundus of the womb, and are extended
and elongated, but adhere to the sides of the uterus so
[Seite 323] firmly, that half of their length only is separate from
it; and, at first sight, they appear to arise from the
middle of the uterus, – a circumstance which gave occa-
sion to an erroneous opinion of the enormous increase of
the fundus of this organ. After this period, the foetus ac-
quires a size more proportional to the capacity of the
ovum, and becoming, at the same time, conglobated to-
gether, acquires a more fixed situation, which it preserves
to the end of pregnancy; the head is inclined to the chest,
and the back bent, and generally rather opposite to one side
of the mother.

580. In the middle of pregnancy, – at the end of the fifth
month, so great has the size of the uterus become, that its
fundus is nearly between the navel and pubis, and pregnan-
cy becomes externally evident. From this period, the foetus,
by its motion, is generally more distinctly perceptible to the
mother: this circumstance, however, occurs at no definite
time.

581. During the remaining five lunar months, the uterus
and foetus continuing to increase, the fundus of the former
reaches the umbilicus about the sixth month; after the eighth,
having risen higher, it approaches the scrobiculus cordis.
In the mean time, the cervix is gradually obliterated, flatten-
ed, and attenuated.

582. In the tenth month, the uterus, overwhelmed, as it
were, with its own bulk, being eleven inches in length and
nine or more in breadth, begins to subside.

Each decidua, but especially the reflexa adhering to
the chorion, having for many months been growing thin-
ner, now almost appears a net-work of short white
fibres.*

[Seite 324]

The larger diameter of the placenta is now nine niches;
its thickness one inch; its weight one pound or upwards.

The length of the umbilical chord is generally eighteen
inches or more.

The weight of a common full grown foetus is usually
seven pounds; its length about twenty inches.*

The quantity of the liquor amnii is too variable to be
defined; but when the foetus is strong, it seldom exceeds a
pound.



NOTES.

(A) The important contents of this and the preceding
paragraph demand farther attention.

Several questions occur. 1. What is the state of the fe-
male organs during the vehemence of desire? 2. How far
does the semen masculinum penetrate? 3. Do the Graafian
vesicles burst from the influence of the semen masculinum,
or merely from the act of copulation, the semen impreg-
nating only the contents of the vesicles after their escape
from the ovaria? 4. At what period do the Graafian vesicles
burst?

1. Mr. Cruikshank, on inspecting the genitals of a
female rabbit during heat, observed appearances nearly
similar to those described by Harvey, Graaf, Ruysch,
[Seite 325] Diembroeck, &c.* He found them all prodigiously turgid
with blood; the vagina was absolutely of a dark mulberry
colour, and on the ovaria were prominent spots, which in-
jection proved to be vascular, and which were swollen
Graafian vesicles; the contents of the vesicles, however,
remained transparent: the Fallopian tubes were also
nearly black, writhing in an extraordinary manner, hav-
ing a strong peristaltic motion, and embracing the ovaria
with their fimbriated extremity so closely as to lacerate
on an attempt to disengage them. These observations
were all confirmed by my friend Mr. Saumarez. Dur-
ing copulation, this state of the organs must be carried to
the highest pitch of intensity.

2. Harvey could never detect semen in the uterus after
copulation.§ Nor De Graaf in the vagina.ǁ Verheyn
found a large quantity in the uterus of a cow, six hours
after copulation. Galen always discovered it in the ute-
rus of brutes after copulation.** Lewenhoeck, in the case
of rabbits. Ruysch found it not only in the uterus, but in
the Fallopian tubes of two women killed in the act of
adultery.†† Postellus, Riolan, Carpus, and Cheselden, also
believed they found it in the uterus.‡‡ Haller once found
it in the uterus of a sheep, forty-five minutes after coition,§§
[Seite 326] and Mr. Hunter is said to have seen it in the uterus of a
bitch which he killed while united with the male, by divid-
ing the spinal marrow.* Haller very justly remarks, that
some of those who assert that they saw semen in the ute-
rus, probably, saw mucus only. He inclines, however, with
almost all physiologists, to the opinion that the semen
does enter the uterus. The length of the penis, the force
of emission, the existence of a bifid glans with two orifi-
ces in the penis of those male animals, the females of
which have two ora uteri, are circumstances of no little
weight in favour of the opinion, that the semen does pene-
trate at least as far as the uterus. But this we shall pre-
sently examine farther.

3. Dr. Haighton, the present lecturer on physiology and
midwifery at Guy’s Hospital, with the view of ascertain-
ing whether it is necessary to impregnation that the semen
[Seite 327] enter the Fallopian tubes, made a number of experiments on
the effects of tying and dividing the tubes in rabbits at dif-
ferent periods relative to coition.* The peristaltic action of
the tubes, and their adhesion to the ovaria during the vene-
real ardour, argue strongly in favour of the semen being con-
veyed along them, because they can hardly be supposed to
begin to occur at this period for the purpose of conveying
the contents of the Graafian vesicle, as this does not burst
till a considerable time after copulation. Dr. Haighton,
indeed, says that these changes in the tubes did not take
place in his experiments till long after copulation (48
hours), – till the ovaria were about to discharge into them
their vesicular fluids. In this he agrees with Bartholin,
De Graaf, Schurig, Deswig and Lang, who maintained,
like him, that the semen, at least as far as examination
went, does not enter the tubes. But Mr. Cruikshank and
Mr. Saumarez, two of the latest experimenters, assert the
contrary in the detail of their experiments, and, as Haller
remarks of the old partizans, the negative experiments of
the former cannot overturn the positive testimony of the
latter, ‘“Eorum experimenta negativa non possunt affirman-
tium fidem evertere:”’ Sbaragli, Verheyn, Hartman, and
Duverney, could find no change in the state of the tubes
at any time, although their negative observations are
completely overthrown by the positive observations of
all others who have enquired experimentally into the
subject. Besides, the great abundance of blood in the
genital organs, during the sexual ardour, must cause the
tubes to enlarge and apply themselves to the ovaria: this, as
[Seite 328] Haller mentions upon the authority of Hartsoeker, occurs
even in the dead body by means of injection. – Dr.
Haighton, however, to prevent the semen from passing
along the tubes, divided one of them in virgin rabbits,
and, after the wound was healed, admitted the animal to
the male. The ovarium on this side contained corpora
lutea equally with the other, proving that the Graafian
vesicles had burst, although the semen could not possibly
have reached the ovarium.* No foetus, however, was dis-
coverable in any instance: on the other side, foetuses
were found equal in number to the corpora lutea. Dr.
Haighton concludes that impregnation may take place
without the advance of semen into the tubes. And his
conclusion is just, according to his test of impregnation, –
the escape of the contents of a Graafian vesicle. But I
apprehend this to be no more deserving the title of a test of
impregnation than the emission of the semen masculinum.
Impregnation is that change wrought by means of the male
semen in the contents of a Graafian vesicle, which ena-
bles them to become a foetus. Now this was never effected
when the tube was divided: although the presence of cor-
pora lutea proved vesicles to have burst, yet a foetus was
in no one instance disovered: in other words, the contents
of the Graafian vesicles were in no one instance impreg-
[Seite 329] nated. Hence I infer, with Mr. Saumarez, that the con-
veyance of semen along the tubes is requisite to im-
pregnation. But Dr. Haighton likewise concludes, that
the bursting of the vesicle is the sympathetic effect of the
semen in the vagina or uterus.* Now although on the
side where the tube was divided the ovarium did dis-
charge the contents of some vesicles, it is not proved that
it did this through the operation of the semen in the va-
gina or uterus. The venereal ardour alone was shewn in
the observations of Mr. Saumarez, as well as in those of
Mr. Cruikshank, to produce, among other great changes
in the sexual organs, the enlargement of the vesicles,
[Seite 330] and it is highly probable that in copulation, where it is car-
ried to its highest point, it is capable of laying the foun-
dation for their rupture. There is more reason to believe
the rupture of the vesicles to be the effect of this than of
the specific action of the semen. Hen birds often lay eggs,
incapable indeed of being hatched, although separated
from the influence of the cock, proving that the oestrum
alone is sufficient in them to apply the tube to the ova-
rium and convey away an ovum. Aristotle and Harvey
relate that many birds lay eggs from mere titillation;
the latter proved it experimentally in the thrush and the
sparrow, and in a favourite parrot belonging to his wife.
Blumenbach is decidedly of opinion that the contents of
a vesicle may escape the ovarium, and a corpus luteum
be formed in virgins, not simply from the analogy of birds,
but also from the accounts which we have of such exam-
ples, corresponding in climate, age, and temperament, with
what should be naturally expected: it is related of young
women, inhabitants of warm countries, and subject to hys-
terical affections.*

How the semen operates upon the ovarian secretion is un-
known. Whether it is directly mixed with it, or whether
its influence is transmitted to the ovarium by sympathy, its
specific operation, both of fecundating and of transmitting
the paternal peculiarities, is a mystery impenetrably conceal-
ed from human curiosity.

[Seite 331]

4. The rupture of the ovarium does not occur till some
time subsequent to coition. Mr. Cruikshank did not see
ova in the Fallopian tubes of rabbits, or orifices in the cor-
pora lutea, till the third day from copulation,* nor ova in the
uterus till the fourth. Dr. Haighton never found any
thing of a regular form in the uterus before the sixth
day.

(B) An instance of superfetation, of the description
granted by Blumenbach, occurred to Mr. Blackaller of
Weybridge. A white woman, of very gay character, left
her husband, and some time afterwards returned pregnant
to her parish, and was delivered in the work-house of
twins, ‘“one of which,”’ says Mr. Blackaller, in an account
which he very handsomely sent me, ‘“was born of a
darker colour than I have usually observed the infants of
negroes in the West Indies; the hair quite black, with the
woolly appearance usual to them, with nose flat, and lips
thick;”’ the second child had all the common appearances
of white children.

The uterus has been sometimes wanting, sometimes
destitute of anterior opening, and sometimes double,§
in which case we may imagine superfetation possible at any
period after the first conception, provided each uterus has a
distinct orifice.

(C) During 57 years, about 78,000 women have been
delivered at the Dublin Lying-in-Hospital, and the pro-
portion of women producing twins, or more, is about 1
in 57.

[Seite 332]

The proportion of males to females, about 10 to 9.*

(D) Fourcroy is almost the only author who has examin-
ed the blood of the foetus, and his observations, as Berze-
lius remarks, ‘“seem to have been made by chance, and
not to be deduced from any experiment;”’ ‘“credible authors
have asserted, that the eye cannot distinguish between
the arterial and venous blood of the foetus.”’ Bichat
could observe no difference in the arterial and venous
blood of the umbilical chords of several guinea pigs, exam-
ined while the mother’s respiration was still continuing after
an opening had been made into the abdomen; ‘“les deux
sangs offroient une noriceur egale.”’§ So too in regard to
dogs.ǁ

The chick, however, in the egg, cut off from all inter-
course with the mother, requires its blood to be purified
by the external air: for if the shell is varnished, the chick
dies: and if, during the latter half of incubation, the shell
is carefully opened, the chorion, to use the eloquent lan-
guage of Blumenbach, presents the most beautiful spec-
tacle in the organic creation; the arteries are seen carry-
ing blood of a bright scarlet, and the veins of a livid red.

SECT. XL.
OF THE NISUS FORMATIVUS.

[Seite 333]

583. Having simply described the phenomena of
conception, and the changes which constant observation
shows to occur both to the ovum and the contained foetus
during pregnancy, we now proceed to those powers, by
which it appears that generation is effected.

584. Even in our memory, some physiologists of repu-
tation have contented themselves with roundly asserting
that true generation never occurs, but that the whole
human race pre-existed in the genitals of our first parents,
in the shape of previously-formed germs, which become
evolved in succession. Some of these imagined the germs
to be the spermatic animalcules of the male;* others
imagined them to exist in the ovaries of the mother.

[Seite 334]

585. This hypothesis of the successive evolution of
germs, pre-formed from the creation, must, if carefully exa-
mined, be rejected.* Not only is the superfluous and use-
less creation which is supposed, of innumerable germs
never arriving at evolution, repugnant to reason, but so
many preternatural conditions and such a multiplica-
tion of natural powers assumed, that it is perfectly
irreconcileable with sound physiology.

Add to this, that, of the phenomena adduced in its
favour, no one is sufficiently consonant with the truth of
nature to prove the hypothesis.§

On the other hand, we have indubitable observations
which refute it directly and completely.

586. The less this hypothesis of evolution, as it is
commonly termed, is found consonant with fact and the
rules of philosophizing, the more strongly does the oppo-
site opinion recommend itself to our notice by its simplicity
and correspondence with nature, supposing, as it does, not
an evolution of fictitious germina by conception, but a true
[Seite 335] and gradual formation of a new conception from the
hitherto formless genital matter.

587. This true generation by successive formation has
been variously described by physiologists, but the follow-
ing we consider as the true account:

1. The matter of which organized bodies, and there-
fore the human frame, is composed, differs from all other
matter in this, that it alone is subject to the influence of
the vital powers.*

2. Among the orders of vital powers, one is eminently
remarkable, and the least disputable of all, – which, while
it acts upon that matter hitherto shapeless, but mature, im-
parts to it a form regular and definite, although varying
according to the particular nature of the matter. To
distinguish this vital power from the rest, permit us to
designate it by the term, – nisus formativus.

3. The nisus formativus occurs to the genital matter,
when this is mature, and committed to the uterus in a
proper condition and under proper circumstances, lays in
it the rudiments of conception, and gradually forms
organs fitted for particular purposes; preserves this struc-
ture during life, by nourishing (455, sq.) the body; and
reproduces (459), as far as it can, any part accidentally
mutilated.

[Seite 336]

588. We therefore think it very probable that those fluids,
which, during a successful coition, are thrown into the
cavity of the uterus (527, 533, 451), (A) require a cer-
tain period for becoming intimately mixed, acted upon,
and matured; that, after this preparatory stage, the nisus
formativus is excited in them, vivifying and shaping the
hitherto shapeless spermatic matter, partly into the beau-
tiful containing ovulum, (565) and partly into the con-
tained embryo; (569) and that this is the reason of our
inability, notwithstanding the present perfection of optical
instruments, to discover, during the first weeks after con-
ception, any thing more than shapeless fluids, without
the faintest trace of the form of an embryo, which, how-
ever, about the third month, as it were, suddenly becomes
observable.

589. We should exceed the limits of these institutions,
were we to adduce many of the arguments which may be
drawn from facts, to illustrate, as, in our opinion, they
most clearly do, the great influence of the nisus forma-
tivus in generation. We will, however, venture to mention,
[Seite 337] as briefly as possible, a few, whose weight will, on a
little close reflection, be sufficiently evident.

590. Such, in the history of hybrid animals, is the
singular experiment of impregnating those which are
prolific, for many generations, with male semen of the
same species, by means of which the form of the young
hybrids become so progressively different from the ori-
ginal maternal configuration, as to approach more and
more to that of the father, till, by a kind of arbitrary
metamorphosis, it is absolutely converted into it.*

591. Such, in our knowledge of monsters, (which, ac-
cording to the hypothesis of evolution, are nearly all
maintained to have pre-existed in the germs from the
first creation,) is the well known fact, that among cer-
tain domestic species of animals, and especially among
sows, monstrosities are very common, while in the ori-
ginal wild variety they are extremely uncommon.

592. While the phenomena of reproduction are all much
more explicable by the nisus formativus than by the pre-
existence of germs for every part, some particular in-
stances, (v.c. that of the nails, which, after the loss of
the first phalanx of the fingers, have been known to be
reproduced on the neighbouring middle phalanx,) admit
evidently of no other solution.

593. From an impartial view of each side of the ques-
tion, it will clearly appear, that the defenders of the
germs must allow to the male semen, not only an exciting
power, as they do, but likewise great formative powers,
and thus their doctrine stands in need of the assistance of
the nisus formativus; while our explanation, on the con-
[Seite 338] trary, is sufficient, without the aid of pre-existing germs,
to explain the phenomena of generation. Nor can there
be any reason for multiplying the entia, as they are called,
unnecessarily (B).



NOTES.

(A) See note A. to section 39, near the end.

(B) The nisus formativus produces a being generally
resembling the parents, but occasionally different. This
subject will be fully treated of in the note on the varieties
of mankind.

It is not probable that the ardour of the procreants
affects the energy of the offspring. But from the days of
Aristotle it has been remarked, that bastards are very fre-
quently endowed with great genius and valour, and both
ancient and modern history certainly afford many such
examples, and the circumstance has been commonly
ascribed to the impetuosity of the parents during their
embraces. Shakspeare, in King Lear, introduces Ed-
mund bursting into this indignant soliloquy:

‘“Why bastard? wherefore base?’
‘When my dimensions are as well compact,’
‘My mind as generous, and my shape as true,’
‘As honest madam’s issue? Why brand they us’
‘With base? with baseness? bastardy? base? base?’
‘Who, in the lusty stealth of nature, take’
‘More composition and fierce quality,’
‘Than doth, within a dull, stale, tired bed,’
‘Go to the creating a whole tribe of fops,’
‘Got ’tween sleep and wake?”’
[Seite 339]

Were this explanation satisfactory, the first fruits of
wedded love would still be on an equality with illegitimate
offspring. If a greater proportion of illegitimate than of
legitimate persons have really rendered themselves illus-
trious, I should attribute their superior energy to the
strength of their parents constitutions, as the weak and
delicate cannot be supposed so frequently to yield to
unlawful passions as the vigorous, and to the necessity in
which such individuals usually find themselves to rely
upon their own exertions.

SECT. XLI.
OF LABOUR AND ITS SEQUELAE.

[Seite 340]

594. The foetus, formed by the powers already de-
scribed, and having reached the period of full maturity,
has to come into the world by means of labour.*

595. This critical period occurs naturally (and physi-
ology treats solely of natural occurrences) at the end of
the tenth lunar month from conception, i.e. about the
39th or 40th week.

596. At that time, the pregnant woman is impelled to
bring forth by an absolute necessity, less under the in-
fluence of the will than any other voluntary function
(287).

597. Physiologists have differed in their explanations
of the causes of so determinate and sudden an event.
After all, the exciting cause of labour must be ascribed to
an eternal law of nature, hitherto equally inexplicable as
so many other periodical phenomena in nature; v.c. the
metamorphosis of insects, the stages of exanthematic
fevers, crises, &c. &c. nor has the mature ovum been in-
aptly compared, ceteris paribus, to fruit, which, when ripe,
falls almost spontaneously to the ground, from the con-
striction of those vessels which previously conveyed its
[Seite 341] nourishment. And in fact it has been remarked, that
the human placenta, at the approach of labour, is con-
tracted, and, as it were, prepared for its separation from
the uterus.

What is usually urged respecting the utmost expansion
of the uterus, and other similar excitements to labour, is
refuted by many circumstances, and, among the rest, by
the numerous examples of extra-uterine, whether tubal or
ovarian, conceptions, in which, at the expiration of ten
months from impregnation, the uterus, notwithstanding its
vacuity, is seized with the customary, though indeed fruit-
less, pains.*

598. Besides this exciting cause, other very powerful
efficient causes are requisite, as must be manifest from the
relation of the ovum to the uterus.

We are persuaded that the proximate and primary cause
is solely the vita propria of the uterus (42, 547).

Among the remote, the most important appears to be
the respiratory effort, excited principally by the great con-
nection of the intercostal nerve with the rest of the nervous
system.

599. We formerly noticed (582) that, during the latter
periods of pregnancy, the uterus somewhat subsided, by
which circumstance the form of the abdomen is somewhat
changed, and the inconveniences induced during advanced
pregnancy, in the function of respiration, are relieved. At
the same time, the vaginal mucus (543) is secreted more
abundantly, the vagina itself is relaxed, the columns of
rugae are almost obliterated, the labia pudendi swell; finally,
[Seite 342] near the approach of labour, the os uteri gradually dilates
into a circular opening.

600. The phenomena of labour generally observe a
regular order of invasion and cessation,* whence accou-
cheurs have divided them into stages, of which the
moderns enumerate four, although they define them va-
riously.

601. In the first, the true pains occur, peculiar in their
nature, proceeding from the loins downwards, in the
direction of the uterus (recurring at intervals, indeed,
during the whole of labour, with various degrees of vio-
lence and frequency), at first mild, when they are called
warning, and the os uteri begins evidently to dilate. At
the same time the abdomen falls still more, the urine is ur-
gent, and abundance of mucus flows from the soft and tumid
genitals.

602. In the second, the pains, increasing, are called pre-
paring,
and, from the compressing effect of the respiratory
organs by means of a strong inspiration, a segment of the
lower part of the membranes of the ovum is protruded
through the uterine orifice into the vagina.

603. In the third, the pains, becoming more excruci-
ating, are called labour pains, and act with still more
violence upon the uterus, which is driven downwards,
and compressed against the foetus, so that the protruded
segment of membranes becomes extremely tense, is burst
asunder, and the greater part of the liquor amnii es-
capes.

604. Finally, in the fourth and last stage, the pains, be-
coming dreadfully violent and agitating, are accompanied
[Seite 343] with great exertions of the woman herself; almost always,
too, with shivering, shrieking, tremor of the knees, See.
The head of the child, now on the verge of birth, pene-
trates, and the face first appears, the vertex usually ad-
hering under the arch of the pubis, and the rest of the head
in the mean time being farther propelled, and revolving
around the impacted vertex as around an axis. Thus the
child comes into the world in the midst of a red discharge,
consisting of a second portion of the liquor amnii mixed
with blood.

605. Soon after the expulsion of the child, the after-la-
bour
commences, attended with a painful though much less
violent exertion, and followed by another hemorrhage, from
that part of the cavity of the womb* to which the placenta
had adhered by means of the decidua crassa.

[Seite 344]

606. Immediately that both burthens are expelled, the
uterus begins gradually to contract, until it acquires its
original form, and very nearly its original dimensions.

607. For about a week after labour, the lochia are dis-
charged, for the most part very similar to the catamenia,
but rather more copious, especially if the mother does not
suckle her offspring. About the sixth day, their red co-
lour becomes fainter, and afterwards is converted into
white. At the same time the uterus is liberated from the
ramenta of the decidua, and having thus completed the
function of pregnancy, is again ready for menstruation or
conception.

SECT. XLII.
OF THE MILK.

[Seite 345]

608. The breasts, most sacred fountains, and, as Gel-
lius Favorinus, the philosopher, elegantly calls them, the
educators of the human race, are intimately connected with
the uterus in various ways. The functions of neither can
properly be said to exist during infancy: at puberty, both
begin to flourish, – when the catamenia appear, the breasts
assume some degree of plumpness: from that period they
undergo either simultaneous changes, – the breasts begin-
ning to swell and secrete milk during the pregnancy of the
womb; or alternate changes, – the catamenia ceasing while
the child is suckled, or the lochia becoming copious if
the child is not suckled, and s. p. Finally, when age
creeps on, the function of each absolutely ceases, – when
the catamenia disappear, both the uterus and the breasts
become equally inert. I omit pathological phenomena;
v.c. those which occur in irregular menstruation, leucorr-
hoea, after extirpation of the ovaria, and in other morbid af-
fections.

609. If this intimate connection is kept in view, we shall
not be astonished that nearly every description of sympathy
formerly mentioned (56) exists between these organs of the
female thorax and abdomen.*

[Seite 346]

610. The influence of the anastomatic sympathy be-
tween the internal mammary and epigastric artery,* al-
though formerly overrated, is evinced by the change
which the latter experiences in its diameter during pregnan-
cy and lactation.

611. Both the uterus and mammae appear to have a kind
of affinity for the chyle, observable in many diseases, and
nearly always in new-born children.

612. The breast of women, belonging to the most cha-
racteristic marks of the human female, both by its form du-
ring the flower of age, and by the longer continuance of this
form after the period of suckling, than occurs in any other
female animal, is composed of a placentiform series of con-
glomerate glands, divided by numerous furrows into larger
lobes, and buried in a mass of fat; the anterior part swells
out particularly with a firmer description of fat, over which
the skin is exceedingly thin.

613. Each of these lobes is composed of still smaller
lobes, and these of acini, as they are termed, to which the
extreme radicles§ of the lactiferous ducts adhere, deriving
a chylous fluid from the ultimate twigs of the internal mam-
mary arteries.

614. These radicles, gradually uniting,ǁ form large
[Seite 347] trunks, corresponding in number with the lobes, about
fifteen in each breast. These are every where dilated into
large sinuses, but have no true anastomosis with each
other.*

615. These trunks terminate in very delicate excretory
canals, which are collected towards the centre, by means
of cellular substance, into the nipple, which, supplied
with extremely fine blood-vessels and nerves, is capable
of a curious erection on the approach of certain external
stimuli.

616. The nipple is surrounded by the areola, which,
as well as the nipple, is remarkable for the colour§ of
the reticulum under the cuticle,ǁ and contains sebaceous
follicles.

617. The secretion of the breast is the milk, well known
in colour, watery, somewhat fatty, rather sweet, bland, re-
sembling in all respects the milk of domestic animals, but
subject to infinitely greater varieties in the proportion of its
constituent parts, and far more difficult of coagulation, from
the great quantity of salt which it contains, and affording no
trace of volatile alkali.**

[Seite 348]

618. When coagulated by means of alcohol, it discovers
the same elements as the milk of other animals. Besides
the aqueous halitus which it gives off when fresh and
warm, the serum, separating from the caseous part, contains
sugar of milk,* acetic acid mixed with phosphate of lime
and of magnesia, and with oil and mucus. The buty-
raceous cream is said to consist of globules of various and
inconstant size, their diameter ranging between 1/200 and
1/600 of a line. (A)

619. The analogy between chyle and blood, and between
both these fluids and milk, renders it probable that the
milk is a kind of reduced chyle, again separated from the
blood before its complete assimilation. This idea is
strengthened by the frequent existence in the milk of the par-
ticular qualities of food previously taken,§ and by the chy-
lous appearance of the watery milk afforded by the breasts
during pregnancy, and immediately after labour.ǁ

[Seite 349]

620. The reason why this bland nourishment of the
foetus becomes, by continued sucking, more thick and
rich, is probably the abundance of lymphatics in the
breasts. Those vessels continually absorb more of the
serous part of the milk, in proportion as its secretion is
more copious and lasting, and, by again pouring this por-
tion into the mass of blood, promote the secretion (477):
after ablactation they take up the residual milk, and mix it
with the blood.

621. The milk is secreted in greatest quantity immedi-
ately after delivery; and, if the infant sucks, amounts to
one or two pounds every twenty-four hours, until the men-
ses, which usually cease during suckling, (556) return.

Occasionally virgins, and new-born infants of either sex,
nay even men,* as well as the adult males of other mamma-
lia, have been known to furnish milk.

622. The abundance of milk excites its excretion, and
even causes it to flow spontaneously: but pressure, or the
suction of the child, completes its discharge.

NOTES.

[Seite 350]

(A) The lower portion of cows’ milk that had stood some
days was found by Berzelius* to have a specific gravity of
1.033, and to contain

Water 928.75
Cheese, with a trace of butter 28.00
Sugar of milk 35.00
Muriate of potash 1.70
Phosphate of potash 0.25
Lactic acid, acetate of potash, with a trace of
lactate of iron

6.00
Earthy phosphates 0.30
–––––––
1000.00
–––––––

The supernatant cream contained

Butter 4.5
Cheese 3.5
Whey 92.0

(B) It may be worth while here to take a general view
of the subject of generation.

Life never occurs spontaneously in matter, but is
always propagated from an organized system already
endowed with it. Such, at least, appears to be the
inevitable conclusion from the facts within our obser-
vation. No instance has been known of a plant or
animal of any species, whose mode of propagation is
ascertained, ever springing up spontaneously; and al-
though in many cases the origin cannot be disco-
vered, yet surely our inability to discover the mode of
[Seite 351] propagation does not justify us in denying the existence
of it; but the general analogy, the discovery of the
modes in which many species propagate, which were for-
merly adduced as instances of spontaneous generation,
and the occasionally manifest source of the difficulties
which obstruct our enquiries, lead necessarily to the belief,
not of the absence of the fact, but of our deficient pene-
tration.*

The simplest mode of increase is by the detachment
and independent existence of a portion of a system. In
this way trees, polypes, some worms, and many animal-
cules, multiply.

Next comes the formation of the rudiments of a per-
fectly new being by the system of another. Thus we
have the seed of vegetables, the ova and foetus of ani-
mals. This occurs by means of two matters, which in
some examples are furnished by the same, and in others
[Seite 352] by different systems. The vegetable kingdom affords
innumerable instances of the former, the acephalous mol-
lusca and the echinus are examples in the animal king-
dom.* Both the vegetable and animal kingdoms abound
in instances of the latter. Here again there are three va-
rieties. The fluid of the male may be applied to the ova
of the female after they are discharged from her body, as
in fish of the bony kind and cephalopodous mollusca;
while being discharged, as in the frog and toad; or it
may be conveyed to the female system, and this either
without the contact of the male, as in vegetables, where
the wind, insects, &c. convey it, or by means of copu-
lation, as in the mammalia, birds, most reptiles, and
some fish.

In the mammalia, one copulation is sufficient for only
[Seite 353] one conception; among poultry its effects are so exten-
sive, that a hen turkey will lay the whole season after
one intercourse with the cock; in the aphis, and some
monoculi, it is sufficient for the impregnation of several
generations.

The ovum after its formation may be nourished by a
fluid enclosed within the same case, and is then hatched
out of the body by the common temperature, as in insects,
or by that of the parent, as in birds, or hatched within the
body of the mother, as in serpents; or it may be nou-
rished by a substance shed around it in the womb, as in
the kangaroo, or by means of an attachment of some of its
vessels to the maternal system, as in the mammalia; some
animals being thus oviparous, others ovo-viviparous, and
others viviparous.

The mode of nourishment after birth is various. Some
are able, without any peculiar arrangement, immediately to
support themselves, for the wisdom of nature ordains the
delivery of each species of animals at that season of the year,
when every thing is in the most favourable state for admi-
nistering to the necessities of the offspring.

Others, many insects for example, are born in the midst
of food, the parent having instinctively deposited the egg
in nutrient matter, either found or carefully collected by
her.

Others have food collected daily by the parents. Others,
as all the dove kind, are fed by a substance secreted from
[Seite 354] the crops of both parents*; others by a fluid secreted by
peculiar glands belonging to the female only. The instinct
which leads the parent carefully to tend the offspring ceases
at the period, when the system of the offspring is sufficiently
advanced to supply its own exigencies.

SECT. XLIII.
OF THE DIFFERENCES IN THE SYSTEM BEFORE AND
AFTER BIRTH*.

[Seite 355]

623. From what has been said relatively to the func-
tions of the foetus still contained within its mother, and
immersed as it were in a warm bath, there must evidently
be a considerable difference between its animal functions
and those of the child which is born, and capable of exerting
its will. The chief points of difference we shall distinctly
enumerate.

642. To begin with the blood and its motion: this fluid
is remarkable, both for being of a darker red, incapable
of becoming florid on the contact of atmospheric air, and
for coagulating less readily and perfectly than after birth.
Its course too is very different in the foetus, whose circu-
lation is connected with the placenta, and who has never
[Seite 356] breathed, from its course after the cessation of this con-
nection with the mother, and after respiration has taken
place*.

625. First, the umbilical vein coming from the placenta,
and penetrating the ring properly called umbilical, runs
to the liver, and pours its blood into the sinus of the
vena portae, the branches of which remarkable vein dis-
tribute one portion through the liver, while the ductus
venosus
Arantii conveys the rest directly to the inferior
vena cava.

Both canals, – the end of the umbilical vein contained in
the abdomen of the foetus, and the venous duct, become
closed after the division of the chord, and the former is
converted into the round ligament of the liver.

626. The blood arriving at the right side of the heart,
from the inferior cava, is in a great measure prevented from
passing through the lungs, and is derived into the left or
posterior auricle of the heart, by means of the Eustachian
valve and the foramen ovale.

627. For, in the foetus, over the opening of the inferior
cava, there is extended a lunated valve, termed, from its
[Seite 357] discoverer*, Eustachian, which usually disappears as ado-
lescence proceeds, but, in the foetus, appears to direct the
stream of blood coming from the abdomen towards an open-
ing, immediately to be mentioned, existing in the septum of
the auricles.

628. This opening is denominated the foramen ovale,
and is certainly the chief cause why the blood which streams
from the inferior cava is poured into the left auricle, during
the diastole of the auricles. A falciform§ valve, placed
over the foramen, prevents its return, and appears likewise
to preclude its course into the left auricle, during the systole
of the auricles. By means of this valve, the foramen gene-
rally becomes closed, in early infancy, in proportion as the
corresponding Eustachian valve decreases, and it more or
less completely disappearsǁ.

629. The blood which enters the right auricle and ven-
tricle principally proceeds from the superior cava, and
flows but in a very small quantity into the lungs, while,
from the right ventricle, which, in the foetus, is remarka-
bly thick and strong for this purpose, it pursues its course
[Seite 358] directly to the arch of the aorta, by means of the ductus
arteriosus
*, which is, as it were, the chief branch of the
pulmonary artery. A few weeks after birth this duct
becomes obstructed, and converted into a kind of dense
ligament.

630. The blood of the aorta, being destined to return, in
a great measure, to the mother, enters the umbilical arteries,
(572) which pass out on each side of the urachus, at the
umbilical opening, and, after birth, likewise become imper-
forate chords.

631. As the function of the lungs scarcely exists in the
foetus, their appearance is extremely different from what
it is after the commencement of respiration. They are
proportionally much smaller, their colour is darker, their
substance denser, consequently their specific gravity is
greater, so that, while recent and sound, they sink in water,
while, after birth, they, caeteris paribus, swim upon its
surface. The right lung has the peculiarity of dilating
during the first inspiration rather sooner than the left§.
The other circumstances attending the commencement
of respiration were described in the section upon that
function.

[Seite 359]

632. From our remarks upon the nutrition of the foetus,
it is clear that its alimentary tube and chylopoietic system
must be very peculiar. Thus, v.c. in an embryo a few
months old, the large intestines very nearly resemble the
small; but during the latter half of pregnancy, being turgid
with meconium, they really deserve the epithet by which
they are commonly distinguished.

633. The meconium is a saburra, of a brownish green
colour, formed evidently from the secreted fluids of the
foetus, and chiefly from its bile, because it is first observed
at the period corresponding to the first secretion of the bile;
and in monstrous cases, where the liver has been absent, no
meconium, but merely a small quantity of colourless mucus,
has been found in the intestines.

634. The coecum is extremely different in the new born
child from its future form, and continued straight from the
appendix vermiformis, &c.*

635. Other similar differences we have already spoken
of, and shall now pass over. Such are the urachus (573),
the membrana pupillaris (262), the descent of the testes in
the male (510, sq.)

Some will be treated of more properly in the next section.
Others, of little moment, we shall entirely omit.

636. This is a favourable opportunity for briefly no-
ticing some remarkable parts, which are, out of all pro-
portion, larger in the foetus, and appear to serve important
purposes in its economy, although their true and prin-
cipal design deserves still further investigation. They
are usually styled glands, but their parenchyma is very
different from true glandular structure, nor has any ves-
tige of an excreting duct been hitherto discovered in
[Seite 360] them. They are the thyreoid, the thymus, and the supra-
renal glands*.

637. The thyreoid gland is fixed upon the cartilage of
the same name belonging to the larynx, has two lobes, is, as
it were, lunated, and full, not only of blood, in which it
abounds in the foetus, but of lymphatic fluid, and becomes,
as age advances, gradually less juicy§.

638. The thymus is a white and very tender structure,
likewise bilobular, sometimes completely divided into two
parts, occasionally containing a remarkable cavityǁ, placed
under the superior part of the middle of the sternum,
always ascending as far as the neck on each side, of
extremely great proportionate size in the foetus, abound-
ing in a milky fluid, becoming gradually absorbed in
[Seite 361] youth, and frequently disappearing altogether in old
age.*

639. The supra-renal glands, called also renes succen-
turiati and capsulae atrabiliariae, lie under the diaphragm
on the upper margin of the kidneys, from which, in the
adult, they are rather more distant, being proportionally
smaller. They are full of a dark fluid of a more reddish
hue in the foetus than in the adult. (A)



NOTE.

(A) It is singular that Blumenbach should omit
notice one of the most striking peculiarities of the foetus –
the very great proportionate bulk of its liver. The pro-
digious size of this organ arises from the distribution of
four-fifths of the blood of the umbilical vein through it,
and probably, as some think, in a certain degree, from the
great quantity of meconium in its biliary ducts. After
birth, no blood is conveyed by the umbilical vein, and the
expansion of the thorax readily expresses the abundance
of meconium; hence the liver must diminish.

This peculiarity, as well as the great size of the thyreoid,
thymus, and supra-renal glands, probably serves some
purpose hitherto undiscovered, but an evident good effect
results from it, in relation to the organs of the thorax.
[Seite 362] In the foetus the lungs are completely devoid of air, and
consequently there cannot be much, if any, circulation of
blood through the pulmonary artery and veins, and the
liver by its magnitude protruding the diaphragm upwards
renders the capacity of the chest correspondently small,
and at the same time it contains an immense proportion of
blood. After birth, the diminished size of the liver allows
a great increase to the capacity of the chest; not only
is full inspiration allowed, and consequently a free passage
to the blood of the pulmonary vessels during inspiration,
as Haller remarks,* but a certain degree of permanent
dilatation of the lungs is allowed, (for much air remains
in the lungs after every expiration), and as the liver con-
tains, immediately after birth, so much smaller a portion
of the blood of the system than before, the greatly in-
creased supply required by the lungs is thus afforded.
See Note B. Sect. 8.

SECT. XLIV.
OF THE GROWTH, STATIONARY CONDITION, AND
DECREASE OF MAN.

[Seite 363]

640. Nothing more remains at present than to survey
at one view the natural course of the life of man, whose
animal functions we have hitherto arranged in classes and
examined individually, and to accompany him through
his principal epochs from his birth to his grave.*

641. The commencement of formation appears to happen
about the third week from conception (569), and genuine
blood is first observable about the fourth, the life of the
foetus at this period being extremely faint (82) and almost
merely that of a vegetable; the motion of the heart (98),
under fortunate circumstances, has been observable at this
time in the human embryo, though long ago detected
by Aristotle in the incubated egg, and since his time
denominated the punctum saliens.

The original form of the embryo is simple, and, as it
were, disguised, wonderfully different from the perfect con-
[Seite 364] formation of the human frame, which deserves to be re-
garded as the grandest effect of the nisus formativus, and
at which it arrives by gradual changes or, if we may so
speak, metamorphoses from a more simple to a more per-
fect form.*

642. The formation of human bone begins, if we are
not mistaken, in the seventh or eighth week. First of
[Seite 365] all, the osseous fluid forms its nuclei in the clavicles, ribs,
vertebrae, the large cylindrical bones of the extremities,
the lower jaw, and some other bones of the face, in the
delicate reticulum of some flat bones of the skull, – of the
frontal and occipital, but less early in the parietal. In
general, the growth of the embryo, and indeed of the
human being after birth, is more rapid as the age is less,
and vice versa.(A)

643. About the middle of pregnancy, certain fluids be-
gin to be secreted, as the fat (486) and bile. In the course
of the seventh month, all the organs of the vital, natural,
and animal functions have made such progress, that if the
child happens to be born at this period, it is called, in a
common acceptation of the word, vital, and regarded as a
member of society.

644. In the foetus, near its full growth, not only is the
skin covered by a caseous matter, but delicate hair appears
upon the head,
and little nails become visible; the mem-
brana papillaris
splits (262); the cartilaginous external
ear becomes more firm and elastic; and in the male the
testes descend. (510 et seq.)

645. About the end of the tenth lunar month, the child
being born, (595), undergoes besides those important
changes of nearly its whole economy, which were formerly
described at large, other alterations in its external ap-
pearance;
v.c. the down which covered its face at birth,
gradually disappears, the wrinkles are obliterated, the anus
becomes concealed between the swelling nates, &c.

[Seite 366]

646. By degrees the infant learns to employ its mental
faculties
of perception, attention, reminiscence, inclina-
tion, &c. whence, even in the early months, it dreams,
and s. p.*

647. The organs of the external senses are gradually
evolved and perfected, as the external ear, the internal
nares, the coverings of the eyes, viz. the supra orbital
arches, the eyebrows, &c.

648. The bones of the skull unite more firmly; the fon-
ticuli
are by degrees filled up; and about eight months
after birth, dentition commences.

649. At this period the child is ready to be weaned, its
teeth being intended to manducate solid food and not to
injure the mother’s breast.

650. About the end of the first year, it learns to rest
upon its feet and stand erect, – the highest characteristic
of the human body.

651. The child now weaned from its mother’s breast
and capable of using its feet, improves and acquires more
voluntary power daily: another grand privilege of the
human race is bestowed upon it, – the use of speech, – the
mind beginning to pronounce, by means of the tongue,
the ideas with which it is familiar.

652. The twenty milk teeth by degrees fall out about
the seventh year, and a second dentition produces, in the
course of years, thirty-two permanent teeth.

653. During infancy, memory is more vigorous than
[Seite 367] the other faculties of the mind, and much more powerful
than at any other period in tenaciously receiving the
impressions of objects: after the fifteenth year, the fire of
imagination burns most strongly.

654. This more lively state of the imagination occurs
very opportunely at puberty, when the body, undergoing
various remarkable changes, is being gradually prepared
for the exercise of the sexual functions.

655. Immediately after the period when the breasts of
the adolescent girl have begun to swell, the chin of the
boy is covered with down, and the phenomena of puberty
manifest themselves in either sex. The girl begins to men-
struate, (554), – an important change in the female eco-
nomy, accompanied among other circumstances, nearly
always by an increased brightness of the eyes and redness
of the lips, and by more evident sensible qualities of the
perspiration. The boy begins to secrete genuine semen
(527), and, at the same time, the beard* grows more abun-
dantly, and the voice becomes remarkably grave.

By the spontaneous internal voice of nature, as it were,
the sexual instinct (71) is now for the first time excited,
and man, being in the flower of his age, is capable of
sexual connection.

656. The period of puberty cannot be exactly defined:
it varies with climate and temperament, but is generally
[Seite 368] more early in the female; so that in our climate, girls
arrive at puberty about the fifteenth year, and young men,
on the contrary, about the twentieth. (B)

657. Soon after this, growth terminates; at various
periods in different climates, to say nothing of particular
individuals and families.* (C)

658. The epiphyses of the bones hitherto distinct from
their diaphyses, now become intimately united, and, as it
were, confounded with them.

659. At manhood, – the longer and more excellent pe-
riod of human existence, life is, with respect to the cor-
poreal functions, at the highest pitch (82), or, in other
words, these functions are performed with the greatest
vigour and constancy; in regard to the mental functions,
the grand prerogative of mature judgment is now afforded.

660. The approach of old age is announced in women
by the cessation of the catamenia (556), and not unfre-
[Seite 369] quently by an appearance of beard upon the chin;* in
men, by less alacrity to copulate: in both, by a senile
dryness and a gradually manifested decrease of vital
energy.

661. Lastly, the frigid condition of old age is accom-
panied by an increasing dulness of both the external and
internal senses, a necessity for longer sleep, and a torpor
of all the functions of the animal economy. The hairs
grow white and partly fall off. The teeth gradually drop
out. The neck is no longer able to give due support to
the head, nor the legs to the body. Even the bones
themselves – the props of the machine – in a manner waste
away, &c.

662. Thus we are conducted to the ultimate line of phy-
siology, – to death without disease,§ to the senile ευϑανασικ,
which it is the first and last object of medicine to pro-
cure, and the cause of which must be self-evident from
our preceding account of the animal economy.

[Seite 370]

663. The phenomena of a moribund person* are cold-
ness of the extremities, loss of brilliancy in the eyes, small-
ness and slowness of the pulse, which more and more fre-
quently intermits, infrequency of respiration, which at
length terminates forever by a deep expiration.

In the dissection of other moribund mammalia the
struggle of the heart may be perceived; and the right
auricle and ventricle are found to live rather longer than
the left, (117).

664. Death is manifested by the coldness and rigidity
of the body, the flaccidity of the cornea, the open state of
the anus, the lividness of the back, the depression and
flatness of the loins (59, Note), and above all, by an
odour truly cadaverous. If these collective marks are
present, there can be scarcely room for the complaint of
Pliny, that one ought not to believe even a dead man.

665. It is scarcely possible to define the natural period
of life, or, as it may be termed, the more frequent and
regular limit of advanced old age.§ But by an accurate
[Seite 371] examination of numerous bills of mortality, I have ascer-
tained a remarkable fact, – that a very large proportion of
Europeans reach their eighty-fourth year, while, on the
contrary, few exceed it (D).

666. On the whole, notwithstanding the weakness of
children, the intemperance of adults, the violence of dis-
eases, the fatality of accidents, and many other circum-
stances, prevent more than perhaps seventy-eight persons
out of a thousand from dying of old age, without disease,
nevertheless, if human longevity* be compared, caeteris
paribus, with the duration of the life of any other known
animal among the mammalia, we shall find that of all the
sophistical whinings about the misery of human life, no
one is more unfounded than that which is commonly made
respecting the shortness of its duration (E).



NOTES.

(A) For a minute account of ossification I refer to Mr.
Howship’s papers in the sixth and seventh volumes of the
Medico-Chirurgical Transactions, and more particularly to
a review of the first paper in the first number of the Annals
of Medicine and Surgery.

(B) Instances continually occur in both sexes of early
puberty, sometimes joined with very rapid growth. The
[Seite 372] mind however does not usually keep pace with the body,
(or rather the brain with the rest of the body) and such
individuals have commonly short lives. Some males are
reported to have been adult before the completion of
their first year. One of the earliest examples of female
puberty is given in the Medico-Chirurgical Transac-
tions:* the girl began to menstruate when not three
years of age, and soon after acquired large breasts, broad
hips, &c. Schurig relates that a little couple, each nine
years of age, married and begot a son.

The activity of the grand organs of generation, – of the
testes in the male and the ovaria in the female, pro-
duces the great changes in the rest of the generative
organs and in the system at large at the period of puberty,
for if they are previously removed, these changes do
not occur, and they appear in general proportional
to the evolution and activity of those organs. This is
well known in regard to animals and man. We perhaps
have no well authenticated instance of the castration of
a woman,§ but when the ovaria have been found defici-
ent, the signs of puberty have not appeared,while
[Seite 373] the absence of the uterus has not been attended by any
deficiency in the general changes.* I must think with
Moreau that many phenomena have been ascribed to
sympathy with the uterus which are really referrible to
the ovaria.

Mr. Hunter made an experiment respecting the removal
of one ovarium only. He took two young sows in all
respects similar to each other, and after removing an
ovarium from one he admitted a boar of the same farrow
to each and allowed them to breed. The perfect sow bred
till she was about eight years old, – a period of almost six
years, in which time she had thirteen farrows, and in all
one hundred and sixty-two pigs; the other bred till she
was six years old, – during a space of more than four
years, and in that time she had eight farrows and in all
seventy-six pigs. Thus it would appear that each ovarium
is destined to produce a certain number only of foetuses,
and that the removal of one, although it does not influ-
ence the number of foetuses produced by the other, causes
them to be produced in a shorter time.

(C) Not only do instances of early puberty and full
growth frequently occur, but likewise of deficient and
exuberant growth. Dwarfs are generally born of the
same size as other children, but after a few years they
suddenly cease to grow. They are said to be commonly
ill-shaped, to have large heads, and to be stupid or mali-
cious,§ and old age comes upon them very early. The
[Seite 374] three foreign dwarfs lately exhibited in London, two men
and one woman, had certainly large heads and flat noses,
but in other respects were well made. The tallest of the
three seemed a sulky creature, but the woman was very
ingenious and obliging, and Simon Paap, the least of the
three, appeared very amiable. He was twenty-eight
inches high and twenty-six years old. They were not re-
lated to each other, and the relations of all were of the
common size. Their countenances were those of persons
more advanced. The smallest dwarf on record was only
sixteen inches high, when thirty-seven years of age.*

The tallest person authentically recorded has never ex-
ceeded nine feet, according to Haller.

The young man from Huntingdonshire also lately exhi-
bited in London was of remarkable height. Although
only seventeen years of age, he was nearly eight feet.
He had a sister of extraordinary height, and many of his
family were very tall. He was, as is usual, born of the
ordinary size, but soon began to grow rapidly. He ap-
peared amiable, and as acute as most youths of his age
and rank. Giants and dwarfs providentially seldom reach
their fortieth year and have not very active organs of
generation.

[Seite 375]

(D) Our countryman Parr married when a hundred
and twenty years of age, retained his vigour till a hundred
and forty, and died at a hundred and fifty-two from ple-
thora induced by a change in his diet. Harvey who dis-
sected him, found no decay of any organ,* and had not
Parr become an inmate of the Earl of Arundel’s family in
London, he probably would have lived many years longer.
Our other countrymen Jenkins, who lived a hundred
and sixty-nine years, is perhaps the greatest authentic
instance of longevity.

It is unnecessary to observe that the height and the
age of men at present are the same as they have been for
thousands of years. It is a common custom to magnify
the past. Homer who flourished almost three thousand
years ago, makes his heroes hurl stones in battle which

–––––––– ου’ δύο γ’ ἂνδρε φέροιεν
Οἶοι νῦν βροτοί εἰσι.

Yet the giant who was the terror of the Israelites, was
not probably more than nine feet in height, and David,
who slew him, and was nearly cotemporary with Homer’s
heroes, says, ‘“The days of our years are threescore and
ten; and if by reason of strength they be forescore
years, yet is their strength labour and sorrow; for it is
soon cut off and we fly away.”’

(E) The functions of the human machine having now
been fully described, it may be of advantage to consider
it in its relation to other animated systems, and to review
the chief varieties in which it appears.

[Seite 376]

Numerous authors have remarked that a gradation
exists among all the objects of the universe, from the Al-
mighty Creator, through arch-angels and angels, men,
animals, vegetables and inanimate matter, down to nothing.

‘“Vast chain of being which from God began,’
‘Natures ethereal, human, angel, man,’
‘Beast, bird, fish, insect, what no eye can see,’
‘No glass can reach, from infinite to thee,’
‘From thee to nothing.”’*

Yet this gradation deserves not the epithet regular or in-
sensible. ‘“The highest being not infinite must be, as has
been often observed, at an infinite distance below infinity.”’
‘“And in this distance between finite and infinite there will
be room for ever for an infinite series of indefinable exist-
ence. Between the lowest positive existence and nothing,
wherever we suppose existence to cease, is another chasm
infinitely deep; where there is room again for endless
orders of subordinate beings, continued for ever and
ever, and yet infinitely superior to non-existence.”’ ‘“Nor
is this all. In the scale, wherever it begins or ends, are
infinite vacuities. At whatever distance we suppose the
next order of beings to be above man, there is room for
an intermediate order of beings between them, and if for
one order then for infinite orders; since every thing that
admits of more or less, and consequently all the parts of
that which admits them, may be infinitely divided. So
that as far as we can judge, there may be room in the
vacuity, between any two steps of the scale, or between
any two points of the cone, for infinite exertion of infinite
power.”’

[Seite 377]

In fact, at how vast a distance do we see the innate
mental properties of man standing above those of the
most sagacious animal: how immensely does the volition
of the lowest animal raise it above the whole vegetable
kingdom; and how deep the chasm between the vital
organisation of the meanest vegetable and a mass of in-
animate matter. Gradation must be admitted, but it is
far from regular or insensible. Neither does it regard
the perfection, nor so much the degree, but the excellence
and combination, of properties, – man, placed at the sum-
mit of the terrestrial gradation, by the excellence of his
mind and the combination of the common properties of
matter, of those of vegetables and of those of animals,
with those peculiar to himself, is surpassed by the dog
in acuteness of smell and by the oak in magnitude, nor is
he more perfect than the gnat or the thistle in its kind.

Bodies consist of particles endowed with certain pro-
perties, without which their existence cannot be conceiv-
ed, viz. extension and impenetrability; with others which
proceed indeed from their existence, but are capable of
being subdued by opposing energies, viz. mobility, in-
ertness; and with others neither necessary to their ex-
istence nor flowing from it, but merely superadded; for
example, various attractions and repulsions, various
powers of affecting animated systems.

Inanimate bodies have no properties which are not ei-
ther analogous to these or dependent upon them; are for
the most part homogeneous in their composition, and
disposed to be flat and angular, increase by external ac-
cretion, and contain within themselves no causes of
decay.

Vegetables, in addition to the properties of inanimate
matter, possess those of Life, viz. sensibility (without
[Seite 378] perception) and contractility;* their structure is beauti-
fully organized, and their surfaces disposed to be round-
ed; they grow by internal deposition, and are destined
in their nature for a period of increase and decay.

Animals, in addition to the properties of vegetables,
enjoy Mind, the indispensable attributes of which are,
the powers of consciousness, perception, and volition;
the two former without the latter were, like vegetable or
organic sensibility without contractility, useless, and the
latter could not exist without the two former, any more
than vegetable or organic contraction could occur with-
out sensibility; nor can the existence of mind be con-
ceived without the faculties of consciousness, perception,
and volition, any more than the existence of matter with-
out extension and impenetrability. The possession of
mind by animals necessarily implies the presence of a
brain for its performance, and of a nerve or nerves for
the purpose of conveying impressions to this brain, and
volitions from it to one or more voluntary muscles. A
system which is not thus gifted certainly deserves not
the name of animal.

[Seite 379]

Notwithstanding the vast interval which of necessity
exists between the animal and vegetable kingdoms, the
lowest animals approach as nearly as possible in organi-
zation, and consequently in function, to vegetable simpli
city. They possess merely consciousness, perception and
volition, with the instinct for taking food, and multiply by
shoots, fixed like vegetables to the spot which they in-
habit. The five senses, instincts, memory, judgment,*
[Seite 380] and locomotive power, with the necessary organs, are
variously superadded, and endless varieties of organiza-
tion constructed, so that air and water, the substance and
the surface of the earth, are all replenished with animals
calculated for their respective habitations.*

[Seite 381]

Man, besides the common properties of animals, has
others, which raise him to an immense superiority. His
mind is endowed with powers of the highest order which
they have not, and his body being, like the bodies of all
animals, constituted in harmony with the mind, that the
powers of the latter may have effect, differs necessarily
in many points of construction from the body of every
animal. Well might the greatest of all uninspired poets
exclaim, ‘“What a piece of work is man! How noble in
reason! how infinite in faculties! in form and moving
how express and admirable! in action how like an angel!
in apprehension how like a god! the beauty of the world!
the paragon of animals!”’*

The true ourang-outang (simia satyrus) approaches
the nearest of all animals to the human subject. Curious,
imitative, covetous, social, placing sentinels and dispos-
ing themselves in a train for the propagation of alarm,
sometimes seeming to laugh, walking occasionally erect,
defending themselves with sticks and stones, copulating
face to face, carrying their young either in their arms
or on their backs, possessing teeth of the same number
and figure as our own, and very lascivious in regard to
our species, the ourang-outangs at first sight afford, if any
of the genus can afford, a little probability to the opinion
of a close connection between monkeys and the human
race. Uncivilized men, too, make a slight approach in
many corporeal particulars, as we shall hereafter find, to
[Seite 382] the structure of other animals, and since also the circum-
stances of their existence call into action few of the pecu-
liar mental powers of our nature, they have been adduced
in corroboration of this opinion. But an attentive exami-
nation displays differences of the greatest magnitude be-
tween the human and the brute creation. These we shall
review under two divisions, the first embracing the mental,
and the second the corporeal characteristics of mankind.

In judging of the mental faculties of mankind, not
merely those should be considered which an unfortunately
situated individual may display, but those which all the
race would display, under favourable circumstances. A
seed and a pebble may not on a shelf appear very dissi-
milar, but if both are placed in the earth, the innate cha-
racteristic energies of the seed soon become conspicuous.
A savage may in the same manner seem little superior to
an ourang-outang, but if instruction is afforded to both,
the former will gradually develop the powers of our na-
ture in all their noble superiority, while the latter will
still remain an ourang-outang. The excellence of man’s
mind demonstrates itself by his voice and hands. Wit-
ness the infinite variety and the depth of thought express-
ed by means of words: witness his great reasoning pow-
ers, his ingenuity, his taste, his conscientious, religious,
and benevolent feelings, in his manufactories, his galleries
of the fine arts, his halls of justice, his temples, and his
charitable establishments. Besides the qualities common
to all animals, each of which he, like every animal, pos-
sesses in a degree peculiar to himself, and some indeed
in a degree very far surpassing that in which any animal
possesses them, for instance, benevolence, mechanical
contrivance, the sense for music, and the general power
of observation and inference, he appears exclusively gifted
[Seite 383] with feelings of religion and justice, with taste, with wit,
and with the faculty of comparing things, and diving into
their causes.*

The corporeal characteristics of mankind are not less
striking and noble. Among the beings beheld by Satan
in Paradise,

‘“Two of far nobler shape, erect and tall,’
‘Godlike erect, with native honour clad’
‘In naked majesty seemed lords of all.”’

The erect posture is natural and peculiar to man.§ All
nations walk erect, and among those individuals who
have been discovered in a wild and solitary state, there
is no well authenticated instance of one whose progres-
sion was on all fours. If we attempt this mode of pro-
[Seite 384] gression, we move either on the knees or the points of the
toes, throwing the legs obliquely back to a considerable
distance; we find ourselves insecure and uneasy; our eyes,
instead of looking forwards, are directed to the ground;
and the openings of the nostrils are no longer at the lower
part of the nose, in a situation to receive ascending odo-
rous particles, but lie behind it. Our inferior extremities
being of much greater length in proportion to the superior,
and the trunk than the posterior, of animals with four ex-
tremities, even in children in whom the proportion is less,
are evidently not intended to coincide with them in move-
ment; they are much stronger than the arms, obviously
for the purpose of great support; the presence of calves,
which are found in man alone, shews that the legs are to
support and move the whole machine; the thigh bones are
in the same line with the trunk; in quadrupeds they form
an acute angle; the bones of the tarsus become hard and
perfect sooner than those of the carpus, because strength
of leg is required for standing and walking sooner than
strength of arm and hand for labour; the great toe is of
the highest importance to the erect posture, and is be-
stowed exclusively on mankind. The superior extremi-
ties do not lie under the trunk, as they would if destined
for its support, but on its sides, capable of motion towards
objects in every direction; the fore arm extends itself
outwards, not forwards, as in quadrupeds, where it is an
organ of progression; the hand is fixed not at right angles
with the arm, as an instrument of support, but in the
same line, and cannot be extended to a right angle with-
out painfully stretching the flexor tendons; the superior
extremity is calculated in the erect posture for seizing and
handling objects, by the freedom of its motions, by the
great length of the fingers above that of the toes, and by
[Seite 385] the existence of the thumb, which, standing at a distance
from the fingers, and bending towards them, acts as an
opponent, while the great toe is, like the rest, too short
for apprehension, stands in the same line with them, and
moves in the same direction. Quadrupeds have a strong
ligament at the back of the neck, to sustain the head; in
us there is no such thing, and our extensor muscles at the
back of the neck are comparatively very weak.* They
have the thorax deep and narrow, that the anterior ex-
tremities may lie near together, and give more support;
the sternum too is longer, and the ribs extend consider-
ably towards the pelvis, to maintain the incumbent visce-
ra; our thorax is broad from side to side, that the arms,
being thrown to a distance, may have greater extent of
motion, and narrow from the sternum to the spine; and
the abdominal viscera, pressing towards the pelvis, rather
than towards the surface of the abdomen, in the erect at-
titude, do not here require an osseous support. The pelvis
is beautifully adapted in us for supporting the bowels in
the erect posture; it is extremely expanded, and the sa-
crum and os coccygis bend forwards below: in animals it
does not merit the name of pelvis; for, not having to
support the abdominal contents, it is narrow, and the
sacrum inclines but little to the pubis. The nates, besides
extending the pelvis upon the thigh bones in the erect
[Seite 386] state of standing or walking, allow us to rest while awake
in the sitting posture, in which the head and trunk being
still erect, our organs of sense have their proper direction
equally as in walking or standing: were we compelled to
lie down like brutes, while resting during the waking
state, the different organs of the face must change their
present situation, to retain their present utility, no less
than if we were compelled to adopt the horizontal pro-
gression; and, conversely, were their situation so chang-
ed, the provision for the sitting posture would be com-
paratively useless.

While some, perversely desirous of degrading their
race, have attempted to remove a grand source of dis-
tinction, by asserting that we are constructed for all fours,
others, with equal perverseness and ignorance, have as-
serted that monkeys are destined for the upright posture.
Monkeys, it is true, maintain the erect posture less awk-
wardly than other animals with four extremities, but they
cannot maintain it long, and, while in it, they bend their
knees and body; they are insecure and tottering, and glad
to rest upon a stick; their feet, too, instead of being
spread for support, are coiled up, as if to grasp some-
thing. In fact, their structure proves them to be neither
biped nor quadruped, but four-handed animals. They
live naturally in trees, and are furnished with four hands
for grasping the branches and gathering their food. Of
their four hands, the posterior are even the more perfect,
and are in no instance destitute of a thumb, although,
like the thumbs of all the quadrumana, so insignificant,
as to have been termed by Eustachius ‘“omnino ridicu-
lus;”’ whereas the fore hands of one variety (simia pa-
niscus
) have not this organ.

It was anciently supposed that man, because gifted with
[Seite 387] the highest mental endowments, possessed the largest of
all brains.* But as elephants and whales surpass him in
this respect, and the sagacious monkey and dog have
smaller brains than the comparatively stupid ass, ox and
hog, the opinion was relinquished by the moderns, and
man was said only to have the largest brain in propor-
tion to the size of his body. But as more extensive ob-
servation proved canary and other birds, and some va-
rieties of the monkey tribe, to have larger brains than
man in proportion to the body, and several mammalia to
equal him in this particular, and as rats and mice too
surpass the dog, the horse, and the elephant, in the com-
parative bulk of their brains, this opinion gave way, in
its turn, to that of Soemmerring, – that man possesses
the largest brain, in comparison with the nerves arising
from it. This has not yet been contradicted, although
the comparative size of the brain to the nerves origin-
ating from it, (granting that they originate from it) is
not an accurate measure of the faculties, because the seal
has in proportion to its nerves a larger brain than the
house dog, and the porpoise than the ourang-outang.

As the human brain is of such great comparative mag-
nitude, the cranium is necessarily very large, and bears a
greater proportion to the face than in any animal. In an
European, a vertical section of the cranium is almost
four times larger than that of the face, (not including the
lower jaw); in the monkey, it is little more than double;
in most ferae, nearly equal; in the glires, solipedes, pe-
cora and belluae, less. The faculties, however, do not
depend upon this proportion, because men of great ge-
[Seite 388] nius, as Leo, Montaigne, Leibnitz, Haller, and Mira-
beau, had very large faces, and the sloth and seal have
faces larger than the stag, horse and ox, in proportion
to the brain, and the proportion is acknowledged by Cu-
vier to be not at all applicable to birds. We are assist-
ed in discovering the proportion between the cranium
and face by the facial angle of Camper. He draws two
straight lines, the one horizontal, passing through the
external meatus auditorius and the bottom of the nos-
trils, the other more perpendicular, running from the
convexity of the forehead to the most prominent part of
the upper jaw. The angle which the latter, – the proper
facial line, makes with the former, is least in the human
subject, from the comparative smallness of the brain and
the great developement of the mouth and nose in ani-
mals. In the human adult this angle is 85°; in the
ourang-outang 67°; in some quadrupeds 20°; and in the
lower classes of vertebral animals, it entirely disappears.

Neither is it to be regarded as an exact measure of the
understanding, for persons of great intellect may have a
prominent mouth; it shows merely the projection of the
forehead, while the cranium and brain may vary greatly
in size in other parts; three-fourths of quadrupeds,
whose crania differ extremely in other respects, have the
same facial angle; great amplitude of the frontal sinuses,
as in the owl and hog, without any increase of brain,
may diminish it, and for this reason Cuvier draws the
facial line from the internal table of the frontal bone.

In proportion as the face is elongated, the occipital
foramen lies more posteriorly; in man consequently it is
most forward. While in man it is nearly in the centre
of the base of the cranium, and horizontal, and has even
sometimes its anterior margin elevated, in most quadru-
[Seite 389] peds it is situated at the extremity of the cranium ob-
liquely, with its posterior parts turned upwards, and is
in some completely vertical. On this difference of situa-
tion, Daubenton founded his occipital angle.* He drew
one line from the posterior edge of the foramen to the
lower edge of the orbit, and another in the direction of
the foramen, passing between the condylcs, and intersect-
ing the former. According to the angle formed, he es-
tablished the similarity and diversity of crania. The in-
formation derived from it in this respect is very im-
perfect, because it shows the differences of the occiput
merely. Blumenbach remarks, that its variations are in-
cluded between 80° and 90° in most quadrupeds, which
differ very essentially in other points.

The want of the os intermaxillare has been thought
peculiar to mankind. Quadrupeds, and even the ape
tribe, have two bones between the superior maxillary,
containing the dentes incisores when these are present,
and termed ossa intermaxillaria, incisoria, or labialia.
Its universal existence in them, however, is not satisfac-
torily established. Man alone has a prominent chin: his
lower jaw is the shortest, compared with the cranium;
and its condyles differ in form, direction, and articula-
tion, from those of any animal: in no animal are the
teeth arranged in such a close and uniform series; the
lower incisores, like the jaw in which they are fixed, are
perpendicular, – a distinct characteristic of man, for in
animals they slope backwards with the jaw bone; the
canine are not longer than the rest, nor insulated, as in
monkeys; the molares differ from those of the ourang-
[Seite 390] outang, and of all the genus simia, by their singularly ob-
tuse projections.

The slight hairiness of the human skin in general, al-
though certain parts, as the pubis and axillae, are more
copiously furnished with hair than in animals; the situa-
tion of the heart lying not upon the sternum, as in qua-
drupeds, but upon the diaphragm, on account of our
erect position, the basis turned not as in them to the
spine, but to the head, and the apex to the left nipple;
the omnivorous structure of the alimentary canal; the
curve of the vagina corresponding with the curve of the
sacrum formerly mentioned, causing woman to be not,
as brute females are, retromingent; perhaps the hymen;
the singular structure of the human uterus and placenta;
the length of the umbilical chord, and the existence of the
vesicula umbilicalis till the fourth month; the extreme
delicacy of the cellular membrane; the absence of the
allantois, of the panniculus camosus, of the rete mirabile
arteriosum, of the suspensorius oculi; and the smallness
of the foramen incisivum, which is not only very large
in animals, but generally double; are likewise structural
peculiarities of the human race.

Man alone can live in almost every climate; he is the
slowest in arriving at maturity, and, in proportion to his
size, he lives the longest; he alone procreates at every
season, and, while in celibacy, experiences nocturnal
emissions. None but the human female menstruates.

Man, thus distinguished from all other terrestrial
beings, evidently constitutes a separate species, – fact
harmonizes with the Mosaic account of his distinct crea-
tion. For ‘“a species comprehends all the individuals
which descend from each other, as from a common pa-
rent, and those which resemble them as much as they
[Seite 391] do each other,”’ and no animal bears such a resem-
blance to man.*

He is subject, however, to great variety, so great in-
deed, that some writers have contended that several races
of men must have been originally created. We shall now
examine the principal of these varieties.

The most generally approved division
of mankind is that of Blumenbach. He makes five va-
rieties; the Caucasian, Mongolian, Ethiopian, Ameri-
can, and Malay. The following are the characteristics
of each.

1. The Caucasian. The skin white; the cheeks red,
– almost a peculiarity of this variety; the hair of a nut
brown, running on the one hand into yellow, and on the
other into black, soft, long, and undulating.

The head extremely symmetrical, rather globular; the
forehead moderately expanded; the cheek bones narrow,
not prominent, directed downwards from the Malar pro-
cess of the superior maxillary bone; the alveolar edge
round; the front teeth of each jaw placed perpendicularly.

The face oval and pretty straight; its parts moderate-
ly distinct; the nose narrow and slightly aquiline, or at
least its dorsum rather prominent; the mouth small; the
lips, especially the lower, gently turned out; the chin
full and round; – in short, the countenance of that style
which we consider the most beautiful.

This comprehends all Europeans, except the Lap-
landers, and the rest of the Finnish race, the western
[Seite 392] Asiatics as far as the Obi, the Caspian, and the Ganges,
and the people of the North of Africa.

M. de Virey subdivides this variety into two parts:*
the one with very light skin and hair and great muscu-
lar strength, including most European nations, as the
Cimbri and Scandinavians, Teutoni, Celts, properly so
called, Goths, Saxons, Icelanders, Britons, Normans,
Francs, Italians, Greeks, and Celtiberians, and even the
Galatae or Asiatic Gauls, who have spread themselves in
Asia Minor, the Morea, Georgia, and Circassia: the
other not so light, including the Vandals, Illyrians or
Sclavonians, Getae, Sarmatae, Gepidae, Thracians, Rus-
sians, Turks, Tartars of the Crimea, Scythians, Persians,
Arabians, Moors, and even the Cisgangetic Hindus.

2. The Mongolian. The skin of an olive colour; the
hair black, stiff, straight and sparing.

The head almost square; the cheek bones prominent
outwards; the space between the eyebrows, together
with the bones of the nose, placed nearly in the same
horizontal plane with the malar bones; the superciliary
arches scarcely perceptible; the osseous nostrils narrow;
the fossa maxillaris shallow; the alveolar edge arched
obtusely forwards; the chin somewhat projecting.

The face broad and flattened, and its parts consequent-
ly less distinct; the space between the eyebrows very
broad as well as flat; the cheeks not only projecting out-
wards, but nearly globular; the aperture of the eye-lids
narrow, linear; the nose small and flat.

This comprehends the remaining Asiatics, except the
Malays of the extremity of the Transgangetic peninsula;
the Finnish races of the North of Europe, – Laplanders,
[Seite 393] &c.; and the Esquimaux diffused over the most northern
parts of America, from Bhering’s Strait to the farthest
habitable spot of Greenland.

In this M. de Virey makes three subdivisions: the
first short, weak, barbarous and cowardly, and lean and
brown even in cold and temperate climates, embracing all
the circumference of the Arctic pole, Spitzberg, Petzora
and Greenland, the Esquimaux, Tschutches, Kamtschat-
kans, Koriaks, Ostiaks, Gakats, Jukagres, Samoides, and
Laplanders: the second, for the most part horridly ugly,
embracing the Eluths and Calmucks, Tunguses, Baskirks,
true Cossacks, Kirghises, Tschouvachs, Burats, Soonga-
rees, the Mantchoos people of the north of China, and
the Tanjutic tribes of Thibet: the third, less ugly, en-
joying a more southern climate and fixed abodes, em-
bracing the Chinese, Japanese, Coresians, Tonguinese,
Cochinchinese, the people of Jesso, many of Thibet, the
Siamese, &c.

3. Ethiopian. The skin black; the hair black and
crisp.

The head narrow, compressed laterally; the forehead
arched; the malar bones projecting forwards; the osseous
nares large; the malar fossa behind the infra-orbitar fo-
ramen deep; the jaws lengthened forwards; the alveolar
edge narrow, elongated, more elliptical; the upper front
teeth obliquely prominent; the lower jaw large and
strong; the cranium usually thick and heavy.

The face narrow, and projecting at its lower part; the
eyes prominent; the nose thick and confused with the
projecting cheeks; the lips, especially the upper, thick;
the chin somewhat receding.

The legs in many instances bowed.

This comprehends the inhabitants of Africa, with the
[Seite 394] exception of those in the northern parts, already included
in the Caucasian variety.

M. de Virey here also makes two subdivisions; the
one embracing the people of the equatorial parts of Afri-
ca, of Nigritia and Guinea, the Madingos, Jaloffs, Caf-
fres, Galla, the inhabitants of Conjo, Angola, the coast
of Zanguebar, Monoëmugi, the interior of Madagascar
and of New Guinea, and lastly, the Papoos: the other of
an olive tint, nearly approaching to black, embracing the
Hottentots, the Namaguese, nearly the whole of New
Holland and some neighbouring islands, as New Caledo-
nia and the island of the Quirds.*

4. The American. The skin of a copper colour; the
hair black, stiff, straight and sparing.

The forehead short; the cheek bones broad, but more
arched and rounded than in the Mongolian variety, not,
as in it, angular and projecting outwards; the orbits ge-
nerally deep; the forehead and vertex frequently deform-
ed by art; the cranium usually light.

The face broad, with prominent cheeks, not flattened,
but with every part distinctly marked, if viewed in pro-
file; the eyes deep; the nose rather flat, but still promi-
nent.

This comprehends all the Americans, excepting the
Esquimaux.

5. The Malay. The skin tawny; the hair black, soft,
curled, thick, and abundant.

The head rather narrow; the forehead slightly arched;
the parietal bones prominent; the cheek bones not pro-
minent; the upper jaw rather projecting.

[Seite 395]

The face prominent at its lower part; not so narrow as
in the Ethiopian variety, but the features, viewed in pro-
file, more distinct; the nose full, broad, bottled at its
point; the mouth large.

This comprehends the inhabitants of the Pacific, Ma-
rian, Philippine, Molucca, and Sanda isles, and of the
peninsula of Malacca.

General Remarks. The colour of the hair thus appears
somewhat connected with that of the skin, and the colour
of the iris is closely connected with that of the hair.
Light hair is common with a white and thin skin only,
and a dark thick skin is usually accompanied by black
hair; if the skin happens to be variegated, the hair also
is variegated; with the milk white skin of the albino, we
find hair of a peculiar yellowish white tint; and where
the skin is marked by reddish freckles, the hair is red.
When the hair is light, the iris is usually blue; when
dark, it is of a brownish black; if the hair loses the light
shade of infancy, the iris likewise grows darker, and when
the hair turns grey, in advanced life, the iris loses much
of its former colour; the albino has no more colouring
matter in his iris than in his skin, and it therefore allows
the redness of its blood to appear; those animals only,
whose skin is subject to varieties, vary in the colour of
the iris; and if the hair and skin happen to be variegated,
the iris is observed likewise variegated.*

[Seite 396]

The Caucasian variety of head, nearly round, is the
mean of the rest, while the Mongolian, almost square,
forms one extreme, having the American intermediate;
and the Ethiopian the other extreme, having the Malay
intermediate between it and the Caucasian.

The Caucasian variety of face is also the mean, while
the Mongolian and American, extended laterally, form
one extreme, and the Ethiopian and Malay, extended
inferiorly, constitute the other. In the first of each ex-
treme, viz. the Mongolian and Ethiopian, the features
are distinct, while in the second, viz. the American and
Malay, they are confused.

Although this division of mankind is well founded and
extremely useful, it is liable, like every artificial division
of natural objects, to many exceptions. Individuals be-
longing to one variety are not unfrequently observed
with some of the characteristics of another;* the charac-
[Seite 397] teristics of two varieties are often intimately blended in
the same individual (indeed all the four varieties run
[Seite 398] into each other by insensible degrees;)* and instances
continually occur of deviation in one or more particulars
from the appearances characteristic of any variety; so
that the assemblage, rather than individual marks, must
frequently be employed to determine the variety.

Particular Remarks. The Caucasian variety is pre-
eminent in all those mental and corporeal particulars
which distinguish man from animals. The general aspect
is dignified; the men appear formed for valour and con-
templation, the women for every sweet attractive grace.
The cranium is very capacious; the area of the face bears
to its area but a proportion of one to four, and projects
little or not at all at the lower parts: the intellectual fa-
culties are susceptible of the highest cultivation. Philo-
sophy and the fine arts flourish in it as in their proper
soil: to it revelation was directly granted.

The Ethiopian variety, when instructed by the Cauca-
sian, has produced instances of mental advancement great
[Seite 399] indeed, but inferior to what the latter is capable of at-
taining. ‘“There scarcely ever,”’ says Hume, ‘“was a
civilized nation of that complexion, nor even an indi-
vidual, eminent either in action or speculation. No
ingenious manufactures amongst them, no arts, no
sciences. On the other hand, the most rude and bar-
barous of the whites, such as the ancient Germans, the
present Tartars, have still something eminent about
them, in their valour, form of government, or some
other particular.”’* Blumenbach, however, possesses
English, Dutch and Latin poetry, written by different
negroes, and informs us, that, among other examples of
distinguished negroes, a native of Guinea, eminent for
his integrity, talents, and learning, took the degree of
doctor in philosophy, at the University of Wittenberg;
and that Lislet, of the Isle of France, was chosen a cor-
responding member of the French Academy of Sciences.
‘“Provinces of Europe,”’ says he, ‘“might be named, in
which it would be no easy matter to discover such
good writers, poets, philosophers, and correspondents
of the French Academy; and on the other hand, there
is no savage people which have distinguished them-
selves by such examples of perfectibility, and even ca-
pacity for scientific cultivation, and, consequently, that
none can approach more nearly than the negro to the
polished nations of the globe.”’ This mental inferiority
is attended of course by a corresponding inferiority of
the brain. The circumference, diameters, and vertical
arch of the cranium being smaller than in the European,
[Seite 400] and the forehead particularly being narrower and falling
back in a more arched form, the brain in general, and
particularly those parts which are the organs of intellect
properly so called,* must be of inferior size. The orbits
on the contrary, and the olfactory and gustatory, or ra-
ther masticatory organs, being more amply evolved, the
area of the face bears a greater proportion to the area of
the skull, – as 1. 2. to 4.; the proportion is greater in the
ourang-outang, and in the carnivora nearly equal. The
senses here situated, as well as that of hearing, are re-
markably acute, and the corresponding nerves, at least
the first, fifth, and facial, of great size.

The ossa nasi lie so flatly as to form scarcely any
ridge; the face, as we have formerly seen, projects con-
siderably at its lower part;§ the lower jaw is not only
long, but extremely strong; the chin not only not promi-
[Seite 401] nent, but even receding, and the space between it and
the lower teeth is small, while that between the upper
teeth and the nose is large; the meatus auditorius is
nearer the occiput, – more remote from the front teeth
than in the European; the foramen magnum occipitale
lying farther back, the occiput is nearly in a line with
the spine; the body is slender, especially in the loins and
pelvis, whose cavity likewise is small; the length of the
fore-arms and fingers bears a large proportion to that of
the os humeri; the os femoris and tibia are more con-
vex, and the edge of the latter, which, in consequence of
hearing the remark from my friend Mr. Fyfe, of Edin-
burgh, I have frequently examined in living negroes, is
very sharp; the calves are placed high; the os calcis, in-
stead of forming an arch, is on a line with the other
bones of the foot, which is of great breadth; the toes are
long; the penis large, and frequently destitute of fraenum.

Mr. White, from whom many of these remarks are
derived, describes the testes and scrotum as small, but
this does not accord with my own experience; the skin
is thicker;* and finally the term of life shorter, than in
Europeans.

Nearly all these facts demonstrate a greater affinity of
the Negro than of the European to the brute creation.
But so slightly inferior to the Caucasians, and so im-
mensely superior to the most intelligent animals, the
poor negro might justly class those of us, who philosophi-
cally
view him as merely a better kind of monkey, or
[Seite 402] who desire to traffic in his blood, not only below himself,
but below apes in intellect, and tigers in feeling and pro-
pensity.

‘“Indica tigris agit rabida cum tigride pacem’
‘“Perpetuam. Saevis inter se convenit ursis.”’*

The Malays have but little hair upon the chin, and
possessing a great developement of the parts of the head
above the ears, are, as might be expected, signalized
for their treachery, cunning, and ferocity, and their pas-
sionate fondness for poetry.

The Mongolians are remarkably square and robust;
their shoulders high; their extremities short and thick.

The Americans have small hands and feet, and are
nearly destitute of beard. Shorter in the forehead than
the Mongolians, they have not so great intellectual dis-
tinction.

Not only have the five varieties their distinctive cha-
racteristics, but the different nations comprehended in
each variety, have each their peculiarities, both mental
and corporeal: among the Caucasians, for example, the
Germans, French, Spaniards and English, are extreme-
ly different from each other. Nay, the provinces of the
same country differ, and the families of the same pro-
vince, and, in fact, every individual has his own pecu-
liar countenance, figure, constitution, form of body, and
mental character.

[Seite 403]

A question here presents itself. – Are the differences
among mankind to be ascribed to the influence of va-
rious causes upon the descendants of two; – or of more,
but all similar, primary parents; – or to original differ-
ences in more than two primary parents? If considera-
tions à priori, analogical and direct facts,
and the history
of mankind,
corroborate in conjunction the first supposi-
tion, there will be no necessity to have recourse to the
bolder second, nor to the third, – the boldest of the three.

Our inquiries on this point should be prosecuted, as
well as all inquiries into nature, without reference to re-
velation. Lord Bacon has observed, that the union of
religious and philosophical investigation is often detri-
mental to the cause of truth.*

If we resolve to make religion and philosophy harmo-
nize before we are certain of being perfectly acquainted
with the meaning of the sacred text, or masters of all the
facts necessary to establish legitimately a philosophical
opinion, the one or the other, or perhaps both, will be
strained and distorted. The truth will be more readily
obtained, if we examine the sense of scripture, indifferent
to the conclusions of philosophy, and inquire into na-
ture, indifferent to the pronunciations of revelation.
They must ultimately agree; for the works and the voice
of the Almighty cannot contradict each other. But this
agreement should be spontaneous; assured that it will
ultimately occur, its absence should have no other in-
fluence upon our minds, than to stimulate us to farther
inquiry, convincing us that either our conclusions are
illegitimate, or our facts deficient; but not inclining us
to deviate in the least from the severest and most inde-
[Seite 404] pendent mode of investigation, nor to force the scripture
from its well established signification.

On the point before us, the Bible speaks positively and
clearly, without the possibility of various interpretation or
corruption of the text, and not only in the account of the
creation, but incidentally in many other places.* It is
[Seite 405] delightful to find nature and history investigated already
so far, as to harmonize with the statement of holy writ:
[Seite 406] but we shall detail the arguments, independently of this
consideration.*

A priori, I think, the universal simplicity of nature’s
causes would induce us to imagine, that as, if the vari-
eties among us are accidental, two individuals were evi-
dently sufficient for the production of the rest of man-
kind, no more than two were originally created. Nor
can I conceive it possible to deduce a contrary presump-
tive argument, from the length of time during which im-
mense portions of the earth must have thus remained
unpeopled. One of nature’s objects seems the existence
of as much life as possible, whether animal or vegetable,
throughout the globe. For this purpose, every species
of animal and vegetable possesses an unlimited power of
propagation, capable of filling the whole world, were op-
portunity afforded it. The opportunities of exertion are
indeed very scanty, compared with the power; one ve-
getable, one animal, stands in the way of another; even
the impediments to the increase of some, act through
them as impediments to others. The constant tendency
of the power of multiplication to exert itself seizes every
opportunity the moment it is presented, and thus nature
[Seite 407] constantly teems with life. The slow increase of man-
kind could not interfere with this apparent object of na-
ture; the deficiency of our race must have invariably
been fully compensated by the opportunities which it
afforded for the multiplication of other existences: for
that man alone was not designed to fill the earth is shown
by the vast tracts of land still but thinly peopled. The
infinitely rare opportunities afforded for the maturity of
the intellectual and moral powers, born with every human
being, may afford still greater surprise than the extent of
country unoccupied by man. After all, the originally
great length of life must have contributed so much to
man’s multiplication, that were food sufficiently supplied,
he might very speedily have covered the earth.

Analogical and direct facts lead us to conclude, that
none of the differences among mankind are so great as to
require the belief of their originality.

Animated beings have a general tendency to produce
offspring resembling themselves, in both mental and cor
poreal qualities.

‘“Fortes creantur fortibus et bonis;’
‘“Est in juvencis, est in equis patrum’
‘“Virtus: nec imbellem feroces’
‘“Progenerant aquilae columbam.”’*

An exception occasionally occurs, much more frequent-
ly indeed in the domestic than the wild state, – the off-
spring differs in some particular from the parents; and,
by the force of the general tendency, transmits to its off-
spring its own peculiarity. By selecting such examples,
a breed peculiar in colour, figure, the form of some one
[Seite 408] part, or in some mental quality, maybe produced. Thus,
by killing all the black individuals which appear among
our sheep, and breeding only from the white, our flocks
are white; while, by an opposite practice, pursued in
some countries, they are black: thus a ram, accidentally
produced on a farm in Connecticut, with elbow-shaped
fore-legs, and a great shortness and weakness of joint
indeed in all four extremities, was selected for propaga-
tion, and the αγχων breed, unable to climb over fences, is
now established:* thus some breeds of hares have horns
like the roebuck: the Dorking fowl has two hind claws;
and fowls indeed are bred in every conceivable variety.
Individuals, distinguished from others by no greater dif-
ferences than those which thus spring up accidentally,
cannot be supposed to belong to a separate species. Upon
the comparison of these differences depends the analogi-
cal argument first employed by Blumenbach. Finding
the ferret (mustela furo) to differ from the pole cat
(putorius) by the redness of its eyes, he concludes it is
merely a variety of the same species, because instances
of this deviation are known to occur accidentally in other
animals; but he concludes the African elephant is of a
[Seite 409] species distinct from the Asiatic, because the invariable
difference of their molar teeth is of a description which
naturalists have never found accidental. Now there ex-
ist among mankind no differences greater than what hap-
pen occasionally in individual species of animals.

The colours of the animals around us, horses, cows,
dogs, cats, rabbits, fowls, are extremely various, black,
white, brown, grey, variegated.

The hair of the wild Siberian sheep is close in sum-
mer, but rough and curled in winter;* sheep in Thibet
are covered with the finest wool, in Ethiopia with coarse
stiff hair; the bristles of the hog in Normandy are too
soft for the manufacture of brushes; goats, rabbits, and
cats of Angouri, in Anatolia, have very long hair, as
white as snow and as soft as silk.§

The head of the domestic pig differs as much from that
of the wild animal, as the Negro from the European in
this respect;ǁ so the head of the Neapolitan horse, deno-
minated ram’s head, on account of its shape, from that of
the Hungarian animal, remarkable for its shortness and
the extent of its lower jaw;** the cranium of fowls at
Padua is dilated like a shell, and perforated by an im-
mense number of small holes;†† cattle and sheep, in some
parts of our own country, have horns, in others not; in
Sicily, sheep have enormous horns:‡‡ and in some in-
[Seite 410] stances, this animal has so many, as to have acquired the
epithet polyceratous.

The form of other parts is no less various. In Nor-
mandy, pigs have hind legs much longer than the fore;*
at the Cape of Good Hope, cows have much shorter legs
than in England; the difference between the Arabian,
Syrian, and German horses is sufficiently known; the
hoofs of the pig may be undivided, bisulcous, or trisul-
cous.

These are regarded by naturalists as but accidental
varieties; yet they equal or surpass the varieties existing
among mankind. We are consequently led by analogy
to conclude, that the differences of nations are not origi-
nal, but acquired; and impose no necessity for believing
that more than one stock was at first created.

Direct facts harmonize with this conclusion. All races
run insensibly one into another, and therefore innumera-
ble intermediate examples occur, where the distinction
between two varieties is lost. Again, no peculiarity
exists in any variety, which does not show itself occa-
sionally in another; many instances of these facts have
been related in the notes to page 396. The difficulty of re-
garding the negro as of the same stock with ourselves
vanishes, on viewing these circumstances, and on reflect-
ing that he and ourselves are two extremes, one of which
may have sprung from the other, by means of several
intermediate deviations, although experience may not
justify the belief, that any single deviation could be of
sufficient magnitude. An instance, however, is related,
in the Philosophical Transactions, of a black family,
which lived where Europeans had never approached, and
[Seite 411] from time to time produced a white child.* Lastly, all
the varieties breed together readily and in perpetuity,
– an assertion which cannot be made in regard to any
different species of animals.

The cause of the differences of our species has been
more or less sought for in climate, alone, or in conjunc-
tion with other external circumstances, by Aristotle, Hip-
pocrates, Cicero, Pliny, Plutarch, Galen, nearly all the
Greek and Roman historians, and poets, Montaigne,
Montesquieu, Buffon, Zimmerman, Blumenbach, Dr.
Smith, of America, &c. Lord Kaimes has denied the
power of these circumstances to produce the diversities
of either mind or body; and Hume has expressly written
an essay, to prove the insufficiency of climate with re-
spect to the varieties of national character. Now the in-
tensity of light unquestionably affects the colour of the
surface, although not to the degree of Ethiopian black-
ness; heat the texture and growth of the hair; and quan-
tity of nourishment the size. But the effects of these cir-
[Seite 412] cumstances are superficial, even on animals necessarily
less protected against their influence than man. The
skulls of foxes belonging to northern regions are not dif-
ferent from those of France or Egypt: the tusks of the
elephant, and the horns of the stag and rein deer, may
acquire a larger size when the food is more favourable
to the production of ivory or horn, but the number and
articulations of the bones, and the structure of the teeth,
remain unaltered.* Nor are these changes any more
than those induced by mechanical means, as pressure,
division, &c. transmitted to the offspring: the child of
the most sunburnt rustic is born equally fair with other
children; even all the children among the Moors are
born white, and acquire the brown cast of their fathers
only if exposed to the sun; although the Jews have
most religiously practised the rite of circumcision from
the days of Abraham, their foreskin still remains to be
circumcised. Were it therefore true that all dark nations
are the inhabitants of hot climates, as the confined know-
ledge of the ancients justified them in believing, it would
still be untrue that the change effected, for instance, in
the colour of the parent’s skin, had descended to the off-
spring. But modern discovery has made us acquainted
with light nations, inhabiting the warmest regions, with
dark nations inhabiting the coldest, and with others of
various shades of colour, although in the same climate.
[Seite 413] Nor are the varieties of mankind more connected with
the varieties of food. In the present state of our know-
ledge, it is impossible fully to account for them.

[Seite 414]

With civilization and barbarism, however, they appear
intimately connected. We should beforehand be inclined
to suppose that the most excellent developement of every
animated species would be effected where all its wants
were best supplied, its powers all duly called forth, and
all injurious or unpleasant circumstances least prevalent:
and vice versa. But experience teaches us that no change
can by any means be brought about in an individual,
and transmitted to the offspring: the causes of change in
a species must therefore operate, not by altering the pa-
rents, but by disposing them to produce an offspring more
or less different from themselves. Such is Mr. Hunter’s
[Seite 415] view of the question,* and it is certainly confirmed by
every fact. Uncivilized nations exposed to the incle-
mency of the weather, supported by precarious and fre-
quently unwholesome food, and having none of the distin-
guishing energies of their nature called forth, are almost
universally dark coloured and ugly; while those who en-
joy the blessings of civilization, i.e. good food and cover-
ing, with mental cultivation and enjoyment, acquire in
the same proportion the Caucasian characteristics. The
different effects of different degrees of cultivation, says
Dr. Smith, ‘‘are most conspicuous in those countries in
which the laws have made the most complete and per-
manent division of ranks. What an immense difference
exists in Scotland between the chiefs and the common-
alty of the highland clans. If they had been separately
found in different countries, the philosophy of some
writers would have ranged them in different species. A
[Seite 416] similar distinction takes place between the nobility and
peasantry of France, Spain, of Italy, of Germany. It
is even more conspicuous in eastern nations, where a
wider difference exists between the highest and the low-
est classes in society. The naires or nobles of Calicut, in
the East Indies, have, with the usual ignorance and pre-
cipitancy of travellers, been pronounced a different race
from the populace; because the former, elevated by their
rank, and devoted only to martial studies and achieve-
ments, are distinguished by that manly beauty and ele-
vated stature, so frequently found with the profession of
arms; especially when united with nobility of descent;
the latter poor and laborious, and exposed to hardships,
without the spirit or the hope to better their condition,
are much more deformed and diminutive in their per-
sons, and in their complexion much more black. In
France, says Buffon, you may distinguish by their aspect
not only the nobility from the peasantry, but the supe-
rior orders of nobility from the inferior, these from citi-
zens, and citizens from peasants.’’ – The field slaves in
America, continues Dr. Smith, ‘‘are badly clothed, fed,
and lodged, and live in small huts on the plantations,
remote from the example and society of their superiors.
Living by themselves, they retain many of the customs
and manners of their ancestors. The domestic servants,
on the other hand, who are kept near the persons, or
employed in the family of their masters, are treated with
great lenity, their service is light, they are fed and
clothed like their superiors, they see their manners,
adopt their habits, and insensibly receive the same ideas
of elegance and beauty. The field slaves are in conse-
quence slow in changing the aspect and figure of Africa.
The domestic servants have advanced far before them in
[Seite 417] acquiring the agreeable and regular features, and the
expressive countenance of civilized society. The former
are frequently ill shaped, they preserve, in a great de-
gree, the African lips, and nose and hair. Their genius
is dull, and their countenance sleepy and stupid. The
latter are straight and well proportioned, their hair ex-
tended to three or four, sometimes even to six or eight
inches: the size and shape of their mouth handsome,
their features regular, their capacity good, and their
look animated.’’*

Dr. Prichard has ‘‘been assured, by persons who have
resided in the West Indies, that a similar change is
very visible among the Negro slaves of the third and
fourth generation in those islands, and that the first ge-
neration differs considerably from the natives of Africa.’’

The South Sea Islanders, who appear to be all of one
family, vary according to their degree of cultivation.
The New Hollanders, for example, are savages, and
chiefly black; the New Hollanders are half civilized, and
chiefly tawny; the Friendly Islanders are more advanced,
and are not quite so dark; several are lighter than olive
colour, and hundreds of European faces are found among
them.

The people of Otaheite and the Society Isles are the
most civilized and the most beautiful: the higher orders
among them have a light complexion, and hair flowing
in ringlets; the lower orders, less cultivated, are less
pleasing.

‘“The same superiority,”’ says Captain King, ‘“which
[Seite 418] is observable in the Erees (nobles) throughout the other
islands, is found also here (Owyhee.) Those whom we
saw were, without exception, perfectly well formed;
whereas the lower sort, besides their general inferiority,
are subject to all the variety of make and figure that is
seen in the populace of other countries.”’

Climate, however, has not been shewn to have no ef-
fect: but its power, being greatly inferior to that of civi-
lization and barbarism, cannot strongly manifest itself,
when acting in opposition to these. In fact, a diminution
of the sun’s influence does dispose to the production of
light varieties: the inhabitants of hilly situations are,
caeteris paribus, fairer than the people below, and persons
of the same tribe and degree of civilization are whiter in
the northern parts of Europe and Asia, than their more
southern neighbours; whiteness, too, is very common in
the north, among animals, which, nearer the equator,
are variously coloured. A pair of brown mice, kept in
a dark place, generate a white offspring.

Perfection, in other words, the highest compatible point
of utility or agreeableness, or of both, is nature’s univer-
sal aim in her productions, but it is in general obtained
slowly, and the more so, in proportion to the excellence
or degree of the qualities to be perfected. Animals and
vegetables have to pass one period, before they burst into
birth, and another, before their full powers and propor-
tions are reached; and man, whose perfections are very
excellent, arrives at his acme very late.

It is in this respect with species as with individuals, –
their improvement is gradual. In conformity with these
observations, we must suppose that man was once far
below the excellence of which he is susceptible, – that
[Seite 419] this was to be acquired slowly; and that, in consequence,
the Caucasian variety did not once exist.

If we believe that he was created in perfection, we
must believe, that, after the fall, his nature experienced
the general change; that he became destitute and wretch-
ed, and destined to reach perfection by slow degrees.
That he was once black, is rendered extremely probable,
by the analogy of animals, among which Mr. Hunter
remarked, that the changes of colour were always from
the darker to the lighter tints.*

It would appear also, from history, that the most an-
cient people of the earth, from whom Europeans are de-
scended, were genuine Ethiopians or Negroes.

[Seite 420]

The history of mankind supports the same inference,
as considerations a priori, and analogical and direct facts.
All the nations of the earth appear to have branched
forth from one quarter. Dr. Pritchard has traced them
with great learning and judgment, and as the subject has
[Seite 421] not been made by myself a matter of original research,
and is far too extensive to be handled here as it deserves,
I must refer to his work, which is both the most recent
and the best, contented with simply inserting his conclu-
[Seite 422] sion, which is the same as Bryant’s, although founded
on different principles.

‘“The countries, bounded on the east and west by the
Ganges and the Nile, on the north by the Caspian lake,
[Seite 423] and the mountainous ridges of Paropamisus and Imaus,
and on the south by the Erythraean sea, or Indian ocean,
appear to have been the region, in which mankind first
advanced to civilization. It is highly probable, that
these countries were the primitive abode of our species,
in which alone, therefore, it can properly be considered
as indigenous.’

‘“In the first ages, previous to the origin of the most
simple arts, while men were as yet too rude to acquire
their sustenance by hunting, (or, if we receive the scrip-
tural account of the deluge, before the woods were filled
with wild animals,) they apparently obtained their food
chiefly by fishing along the sea shores, or depended for a
still more precarious supply on the scanty fruits of the
earth. In this state, they would, of necessity, lead a
[Seite 424] wandering life, and extend themselves widely. Differ-
ent tribes of ichthyophagi, or of roaming savages, were
scattered on each side of the primitive region, wherever
an easy progress lay open to them, along the coast or
through the woods of Africa, and around the shores of
the Indian islands of New Guinea, and Australasia.
The descendants of these dispersed races are still found
in the same abodes, nearly in their original unimproved
condition, savages and negroes, such as we have seen
that the stock of their ancestors, the primeval inhabitants
of Egypt and India, were.’

‘“These were the most ancient colonies, which emi-
grated into the distant parts of the earth. Accordingly,
they exhibit no affinities with the central nations, in their
languages, manners, or superstitions. For they went
forth when language was as yet imperfectly formed, be-
fore manners had acquired any peculiar character, and
previous to the age of idolatry.’

‘“The condition of mankind, in their primeval seats,
improved. They became hunters, and afterwards shep-
herds. Sabaism, or the worship of the heavenly bodies,
now prevailed among them. Some tribes of hunters, and
perhaps of shepherds, ascended the chain of Paropamisus,
and spread themselves gradually over the high central
plains of Asia, on one side into Siberia and Scandinavia,
and on the other into Kamtschatka, and through the adja-
cent, and probably then connected, continent of America.
These are the Mongoles, and other similar races, whom we
have traced through Asia and the north of Europe, and
the primitive inhabitants of the New World. In the lan-
guages of these nations, though much diversified, and very
imperfect in structure, a certain degree of affinity maybe
clearly marked. In their superstitions, vestiges remain of
the primitive Sabaism, even in their more distant settle-
[Seite 425] ments. Their physical characters resemble. In other
particulars, proofs may be collected in many remote re-
gions, of the common origin of these races.’

‘“Meanwhile agriculture was invented in Asia, and
the division of labour connected with the institution of
casts, which seems to have extended through all the
primitive regions, gave a new character to human so-
ciety. The establishment of a governing or military
class, and of a sacerdotal class, gave birth to political
order. The priests mingling allegory and fable with the
early Sabaism, and with the relics of genuine theism and
true historical tradition, which had probably been pre-
served in a few families, formed a complex system of
mythology. The mysteries were invented. Philosophy
began to be cultivated, and a more perfect language was
formed.’

‘“The Celtae under their Druids, a branch of the east-
ern hierarchy, advanced into the furthest west, where
perhaps some vestiges of previous colonists may be
found. They carried with them the mysteries, the doc-
trine of metempsychosis, the rites of polytheism, the phi-
losophy, and the language of the east.’

‘“The Pelasgian and Thracian races established them-
selves in Asia Minor and passed the Hellespont into
Thrace. The former colonized Greece and Italy; the
latter passed to the northward of the Danube into the
Dacian or Getic country. Tribes of this nation wander-
ed at a later period through the forests of Germany,
where they multiplied and encroached upon the Celtae.
Lastly, the Medes, delighting in their herds of horses,
advanced through the Euxine borders into Scythia and
Sarmatia.’

[Seite 426]

‘“That all these nations, the Celtae, the Pelasgi, the
Goths, and the Sarmatae, were comparatively late colo-
nists from Asia, we may safely assert, when we consid-
er the strong affinities discoverable in their systems, in
their religious rites and doctrines, and in their dialects,
which are clearly branches of the Sanscrit and old Per-
sic, and when we remark that most of them may be
traced in history still preserved, from their primitive
settlements in the East.”’

Our inevitable conclusion thus coincides with the
Mosaic account – that the whole human race is the off-
spring of the same parents.

THE END.

Notes
*.
[[v]]

Pref. to the Institut. Medic. Leyden. Fourth edition.

†.
[[v]]

Pref. to the Prim. lin. Physiol. Gottingen. First edition.

*.
[Seite 1]

Thus, long ago, the author of the book, generally included among the
writings of Hippocrates, Epidemic, VI. Sect. 8. § 19. said ‘“Those things
which contain, are contained, or moved in us with force, are to be consider-
ed.”’ This celebrated passage gave origin to the excellent work of Abr.
Kaau Boerhaave, entitled, ‘“Impetum faciens dictum Hippocrati per corpus
consentient
’ L.B. 1745. 8 vo.

*.
[Seite 2]

The great preponderance of the fluids is strikingly exemplified in an entire,
but perfectly dry mummy of an adult Guanche, one of the original inhabitants
of the Island of Teneriffe. It was sent to my anatomical museum by the il-
lustrious Banks; and though all its viscera and muscles are preserved, does
not exceed 7 1.2 lbs. in weight.

*.
[Seite 3]

J. Hunter’s Treatise on the Blood, Inflammation, &c. London, 1794,
4to.

*.
[Seite 4]

They divided the body into similar or homogeneous parts as the bones,
cartilages, muscles, tendons, &c.; and dissimilar, composed of the similar,
as the head, trunk, limbs, &c.

†.
[Seite 4]

Physiologists have variously estimated the quantity of the blood in a well
formed adult. Allen, Mullen, and Albeildgaard, make it scarcely more
than 8 pounds; Borelli, 20; Haller, 30; Hamberger, 80; J. Keil, 100. The
former are evidently nearer the truth.

‡.
[Seite 4]

J. Martin Butt. De spontanea sanguinis separatione. Edinb. 1760, 8vo.
reprinted in Standifort’s Thesaurus, vol. ii. J.H.L. Bader. Experimenta
circa sanguinem.
Argent. 1788, 8vo.

§.
[Seite 4]

The elements of aeriform fluids of course exist in the blood; that they are
not, however, in the elastic state, as so many physiologists formerly believed,
was clearly shewn in some experiments made by me during the year 1812,
upon other mamalia. I found that a small portion of the purest air infused
into the jugular vein, excited palpitations, drowsiness, convulsions; and if
the quantity was rather increased, even death ensued. I have detailed these
[Seite 5] experiments in the Medic. Biblioth. vol. i. 177. The illustrious Bichat ob-
served the same effects in his experiments. Journal de Saute, &c. de Bor-
deaux.
T. 11. 61

*.
[Seite 6]

J. Bostock, in The Medico-Chirurgical Transactions, published by the
Medical and Chirurgical Society of London,
vol. i. 1809. p. 46.

*.
[Seite 7]

G. Chr. Reichel, De Sanguine ejusque motu experimenta. Lips. 1767.
4to. p. 27, fig. 3, g.g.

†.
[Seite 7]

Unwilling as I am to follow the example of those, who especially in mo-
dern times, delight in changing scientific terms, I cannot but think that the
word, oxygenized and carbonized may be advantageously substituted for arte-
rial and venous; because arterial blood is contained in some vessels called
veins, v.c. the pulmonary and umbilical, while, on the other hand, venous
blood is contained in the pulmonary and umbilical arteries. In the same man-
ner, the veins of the chorion in the incubated egg contain arterial, the arte-
ries venous, blood, to use these expressions in their common acceptation.

‡.
[Seite 7]

Consult among others whom we shall recommend in the chapter on
respiration, Chr. Girtanner in the Journal de Physique, August 1790.

[Seite 8]

Fourcroy in the Annales de Chemie, T. vij.

Hossenfratz, ibidem. T. ix.

J. Ferd. h. Autenreith, Experimenta et observata de sanguine praesertim
venoso.
Stuttg. 1792, 4to.

*.
[Seite 8]

By Will. C. Wells, Philos. Trans. 1797, the redness of the blood in gene-
ral is rather ascribed to the peculiar fabric of the globules, and its various de-
grees and changes simply to the reflection of light.

†.
[Seite 8]

Such are those spurious membranes found exuded on the surface of in-
flamed viscera, v.c. those cellular connections between the lungs and pleura
after peripneumony, and the tubes observed within the bronchiae after
croup; such also are those artificial ones called, after their inventor, Ruyschian,
and made by stirring fresh blood about with a stick.

*.
[Seite 10]

Berzelius discovers lactic acid free or combined in all animal fluids. It
was first noticed by Scheele, but is generally regarded as a combination of
acetous acid with animal matter.

†.
[Seite 10]

See Dr. Bostock’s papers in the first, second, and fourth volumes of
The Medico Chirurgical Transactions, and Berzelius in the third.

*.
[Seite 12]

Hier. Dav. Gaubius’ Spec. exhibens ideam generalem solidarum c. h. parti-
um.
Lugd. Bat. 1725, 4to.

†.
[Seite 12]

Abr. Kaau Boerhaave, on the cohesion of the solids in the animal body, in
the Nov. Comm. Acad. Petropolit. T. iv. p. 343, sq.

‡.
[Seite 12]

The parallel and reticulated bony fibres are most striking in the radiated
margins of the flat bones, as we find these in young heads much enlarged by
hydrocephalus. I have, in my museum, a preparation of this kind, where, in
the sphenoid angles of the parietal bones, the fibres are an inch or two in
length, distinct and delicate. The hardest parts, the bony and vitreous por-
tions of the teeth, exhibit a structure similar to that which in the zeolite, ma-
lachite, hematite, &c. all mineralogists call fibrous.

*.
[Seite 13]

Dav. Chr. Schobinger (Praes. Hallero) De telae Cellulosae in fabrica c. h.
dignitate,
Gotting. 1748, 4to. Sam. Chr. Lucae at the end of his Observ.
Anatom, circa nervos arterias adeuntes.
Francof. 1810, 4to.

†.
[Seite 13]

Casp. Fr. Wolff, in the Nov. Act. Petropol. T. vi. p. 259.

*.
[Seite 14]

I have treated this point at large in my work, De Generis humani varie-
tate nativa,
p. 46, edit. 3.

*.
[Seite 16]

A host of authors on the vital powers will be found in Fr. Hildebrandt’s
Lehrbuch der Physiologie, p. 54, sq. edit. 2, 1809, to whom we may add E.
Bartel’s Systemat. Entwurf einer Allgemeinen Biologie. Francof. 1808, and J.
B.P.A. Lamarck’s Philosophie Zoologique, Paris, 1809, 11 vols. 8vo.

*.
[Seite 17]

‘“Life formally is nothing more than the preservation of the body in
mixture, corruptible indeed, but without the occurrence of corruption.”’
Stahl.

‘“What we call life is opposite to putridity.”’ J. Junker

*.
[Seite 19]

That Haller and Theoph. de Bordeu, the chief writers on the mucous
tela, did not form a just conception of this vital power, will be evident from the
latter’s Recherches sur le Tissu Muqueux, Par. 1767, 8vo. and the dissertation
of the former on Irritability in the Dictionnaire Encyclopedique d’Yverdun.
T. xxv.

†.
[Seite 19]

Haller De Partibus Corp. Hum. iritabilibus in the Nov. Comm. Soc. Reg.
Scient.
Gotting. T. iv.

‡.
[Seite 19]

I have spoken of these at large both in my treatise De Iridis Motu 1784,
and my programma De Vi Vitali Sanguini deneganda 1795.

§.
[Seite 19]

On the vita propria of the absorbent vessels consult Seb. Justin. Brag-
mans, De Causa Absorptionis per Vasa Lymphatica. Ludg. Bat. 1795, 8vo.

[Seite 20]

On the peculiar vital properties of the arteries consult Chr. Kramp, Kritik
der Praktischen Arzneikunde.
Lips. 1795, 8 vo.

Many of the phenomena now mentioned are ascribed by others to an or-
gasm, to use an old expression, struggling from the centre to the circumfe-
rence, and lately designated vital turgor.

*.
[Seite 20]

Fouquet in the Dictionarie Encyclopedique de Paris T. xv. Art. Sensibilité

†.
[Seite 20]

Consult C. Fr.Kielmeyer Uber die Verhältnisse der organischen Krafte inder
Reihe der verschiedenen organisationen,
1793, 8vo H.F. Link Uber die Lebens-
kräfte in naturhistorischer Rücksicht. Rostoch.
1795, 8vo.

*.
[Seite 21]

See Abildgaard in the Acta Reg. Soc. Med. Havniens. T. 1.

*.
[Seite 22]

V.C. Dan. Bernouilli De Respiratione, Basil, 1721.

[Seite 23]

‘“Respiration supplies a very subtle air, which, when intimately mixed
with the blood, greatly condensed, conveyed to the moving fibres, and al-
lowed by the animal spirits to exert its powers, inflates, contracts and moves
the muscles, and thus promotes the circulation of fluids, and imparts motion
to mobile parts.”’

*.
[Seite 23]

Laur. Bellini De Sanguinis Missione, p. 165–193.

Sylvest. Douglas De Stimulis. Lugd. Bat. 1766.

*.
[Seite 24]

Montesquieu De l’Esprit des Lois. T. ii. p. 34. London, 1757,
8vo.

†.
[Seite 24]

Jo. Casp. Hirzel De Animi laeti et erecti efficacia in Corpore sano et aegro.
Lugd. Bat. 1746.

‡.
[Seite 24]

Called Le Tact ou le Gout particulier de chaque Partie, by Theoph. de
Bordeu, in his Recherches Anatomiques sur les Glandes, p. 376. sq.

§.
[Seite 24]

Sam. Farr on Animal Motion, 1771, 8vo. p. 141.

Jo. Mudge’s Cure for a recent catarrhous Cough. Edit. 2. 1779, 8vo. p.
238.

Gilb. Blane On Muscular Motion, 1788, 4to. p. 22.

J.L. Gautier De irritabilitatis Notione, &c. Hal. 1793, 8vo. p. 56.

ǁ.
[Seite 24]

J.H. Rahn De Causis Physicis Sympathiae. Exerc. 1. – vii. Figur. from
1786, 4to.

Sylloge selectiorum opusculor de mirabili sympathia quae partes inter. diversas
c. h. intercedit.
Edited by J.C. Tr. Schlegel. Lips. 1787, 8vo.

*.
[Seite 25]

G. Egger (the author Lawr. Gasser) De consensu nevorum. Vindob. 1766,
8vo.

†.
[Seite 25]

J.G. Zinn’s Observations on the different Structure of the Human Eye
and that of Brutes. Diss. ii. 1757. in the Comment Soc. Reg. Scient. Gotting.
antiquiores.
T. 1.

‡.
[Seite 25]

Consider the constant sympathy of heat between certain parts of some
animals, v.c. of the hairs with the fauces, in variegated rabbits, sheep,
dogs, &c. of the feathers with the covering of the bill and feet in varieties of
the domestic duck. That many such instances are not referable to the
influence of nerves, I contended in my Comm. de Motu iridis, p. 12, et seq.
and also in my work de Generis humani varietate nativa, p. 361. et seq.

§.
[Seite 25]

Innumerable pathological phenomena will be found explained by this
sympathy in S. Th. Soemmerring’s De Morbis Vasorum Absorbentium Diss.
quae praemium retulit.
Francof. 1795. 8vo.

*.
[Seite 27]

Hence after death, even in young subjects full of juices, the back, loins,
and buttocks, having for some time lost their vital tone, are, if the body is
supine, depressed and flattened by the superincumbent weight, which now
is not resisted: this appearance I regard among the indubitable signs of
death.

†.
[Seite 27]

Treatise on the Blood, &c. Introduction.

*.
[Seite 28]

Anatomie Generale. T. i. p. 183, sq.

†.
[Seite 28]

Consult Whytt’s Observations on Nervous Diseases. Ch. i.

*.
[Seite 29]

Consult Alex. Chrichton’s Inquiry into the nature and origin of mental
derangement, comprehending a concise system of the Physiology and Pathology
of the human mind.
Lond. 1798, 2 vols. 8vo. Imm. Kaut’s Authropologie in
pragmatischer Hinsicht.
Könisb. 1798, 8vo. Chr. Meiner’s Untersuchungen
über die Denkkräfte und Willenskräfte des Menschen nach Anleitung der Er-
fahrung.
Gött 1806, 2 vols. 8vo.

*.
[Seite 30]

The difference, analogy, and relation of memory and judgment, have
given rise to various controversies. Some celebrated psychologists have in-
cluded both under the word imagination taken in its most comprehensive
sense, and have divided it into two species: memory, representing for-
mer ideas, and the facultas fingendi, representing such ideas only as are
formed by abstraction. They again divide memory into sensitive (imagina-
tion in a stricter sense) and intellectual.

Their facultas fingendi, they also subdivide into intellectual (the more ex-
cellent,) and phantasy, obeying mechanical laws. Feder’s Grundsätze der
Logik und Metaphysik.
Götting. 1794. p. 20.

†.
[Seite 30]

Of this the highest prerogative of the human mind, by which man
exerts his dominion over other animals, and indeed over the whole creation,
I have fully treated in my book De Gen. Hum. Var. Nat. p. 32, ed. 3.

*.
[Seite 32]

Theod. G. Aug. Roose Uber die Krankheiten der Gesunden, Gotting,
1801, 8vo.

G. Chr. Klett, Tentamen evolvendi notionem de sanitate hominis, Wirceb.
1794, 8vo.

*.
[Seite 33]

Galen, quod animi mores corporis temperaturas sequantur.

St. J Van Geuns, De corporum habitudine animae huiusque virium indice ac
moderatrice.
Harderv. 1789. 4to.

†.
[Seite 33]

Galen, De sanitate tuenda, L. 1.

‡.
[Seite 33]

W.F. Ad. Gerresheim, De sanitate cuivis homini propria. Ludg. Bat.
1764, 4to.

§.
[Seite 33]

Lavater’s Physiognomische Fragmente. T. iv. p. 343.

W. Ant. Ficker’s Comment de temperamentis hominum quatenus ex fabrica
et structura corporis pendent
Gott. 1791, 4to.

J.N. Hallé in the Mem. de la Soc. Médicale d’Emulat. T. iii. p. 342.

ǁ.
[Seite 33]

To the numerous arguments by which the moderns have overthrown the
doctrine of the ancients, and proved that the temperament depends on the
living solids, rather than on the nature of the blood, I may add the celebrated
example of the Hungarian sister twins, who, at the beginning of the last cen-
tury, were born united at the lower part of the back, and attained their twen-
ty-second year in this state. They were, as is well known, of very different
temperaments; although dissection discovered, that their sanguiferous sys-
tems anastomosed so considerably, that the blood of both must have been the
same.

*.
[Seite 34]

Kant, l. c. p. 257, sq.

†.
[Seite 34]

Feder in the Untersuchung über den menschlichen Willen. T. ii. p. 49.

*.
[Seite 35]

Galen De Consuetudine.

G E. Stahl. De consuetunis efficacia generli in actibus vitalibus. Hal.
1700, 4to.

H. Cullen, De Consuetudine. Edinb. 1780, 8vo.

C. Natorp, De vi consuetudinis. Gott. 1808, 4to.

†.
[Seite 35]

See Platner’s Quaest. physiol. p. 31. Versuch einer Anthropologie. T. i.
p. 100, 222, and my own remarks on the bad foundation of this division, in
the preface to my Enchiridion Anat. Comparate, p. xi. sq.

‡.
[Seite 35]

J.J. Bernhard’s Versuch einer Vertheidigung der alten Eintheilung der
Functionen. und einer Classification des organisirten Körper, nach denselben,

Erf. 1804, 8vo.

*.
[Seite 36]

Treatise on Febrile diseases. Ch. iii. Sect. 3. First Edition, 1799 Paper
read to the Royal Med. Society of Edinburgh,
1791, or 1792, and inserted in its
Records. Essay on Opium,
1795. – Edinburgh Med. and Surgical Journal,
July, 1809, p. 301, sq.

†.
[Seite 36]

Recherches Physiologiques sur la Vie et la Mort.

*.
[Seite 37]

Bichat’s Antomie Generale, Tom. 1, cii. et. ciii.

*.
[Seite 39]

The following is Bichat’s table of the properties of the living body.

[Seite 40]
xxx

Although these are the general properties of the living frame, yet each
part has besides some pecularity, altogether inexplicable, not in the least,
I think, to be accounted for on Bichat’s supposition of each part possess-
ing a certain degree of organic sensibility in relation to its fluids. What
causes the vessels of muscle to produce muscle; of bone, bone; of mem-
brane, membrane; what causes the secreting vessels of the liver to form
bile, and of the testes semen, we know not. These circumstances may be
called by Blumenbach, after Bordeau, vitae propria; but it must be carefully
remembered that this expression simply denotes a fact, and affords no
explanation.

*.
[Seite 43]

In universum sane post omnia quae super hoc argumento sive me-
ditando sive experiundo hactenus elicere licuit, nulli humorum nostri
corporis genuina vis vitalis tribuenda videtur, si unice a genitali utriusque
sexus latice discesseris, utpote cui jam arte quam uterino cavo exceptus et
intime mixtus in foetus formationem abit, vitales inhaerere vires formativas,
praeter alia paterni vultus in nepotes propagata similitudo, aliaque id genus
phaenomena haud infitianda demonstrare videntur. Comment. Soc. Reg.
Societ. Gotiing.
vol. ix. p. 12.

†.
[Seite 43]

The doctrine of the life of the blood was maintained by Harvey
(Exercit. L. De generationis ordine, &c.) Glisson (De ventriculo et
intestinis
) and Albinus (Blumenbach’s Commentat. l. c.) I am sur-
[Seite 44] prised that Moses should be adduced as authority for this opinion.
When he says (Leviticus, ch. xvii. 11, 14.) ‘“For the life of the flesh is
in the blood”’ – ‘“For it is the life of all flesh,”’ he can mean only that when
it is withdrawn life ceases, – that it is necessary to the life of animals. He
says, (v. 14.) ‘“the blood of it is for the life thereof.”’

*.
[Seite 44]

Consult Hunter’s Treatise on the Blood, &c. p. 1, ch. 1.

*.
[Seite 45]

See note (E) to Sect. 44.

*.
[Seite 46]

Parentibus liberi similes sunt non vultum modo et corporis formam, sed
animi indolem, et virtutes, et vitia. – Claudia gens diu Romae floruit impigra,
ferox, superba: Eadem illachrymabilem Tiberium, tristissimum Tyrannum
produxit: tandem in immanem Caligulem et Claudium, et Agrippanam, ip-
sumque demum Neronem, post sexcentos annos desitura. Gregory’s Con-
spectus Medicinae Theoret.

*.
[Seite 47]

That evil spirits had never more hand in causing insanity than indigestion
is clearly proved to every medical man in Farmer’s Essay on the Demoniacs
oj the New Testament.

†.
[Seite 47]

The Analogy of Religion natural and revealed to the Constitution
and Course of Nature.
By Joseph Butler, LL. D. Lord bishop of
Durham, p. 33.

*.
[Seite 48]

The great Paley’s sermon on the state after death contains the follow-
ing conclusions from various intimations in the New Testament ‘“First,
that (at the resurrection) we shall have bodies.’

‘2. That they will be so far different from our present bodies, as to be suit-
ed, by that difference, to the state and life into which they are to enter,
agreeably to that rule which prevails throughout universal nature, that the
body of every being is suited to its state, and that when it changes its state
it changes its body.’

‘3. That it is a question by which we need not be at all disturbed whether
the bodies with which we shall arise be new bodies, or the same bodies under
a new form; for,’

‘4. No alteration will hinder us from remaining the same, provided we
are sensible and conscious that we are so, any more than the changes which
our visible person undergoes even in this life, and which from infancy to
manhood are undoubtedly very great, hinder us from being the same, to
ourselves and in ourselves, and to all intents and purposes whatso-
ever.’

‘Lastly, That though from the imperfection of our faculties, we neither
are, nor without a, constant miracle upon our minds, could be made able
to comprehend the nature of our future bodies, yet we are assured that
the change will be infinitely beneficial; that our new bodies will be in-
finitely superior to those which we carry obout with us in our pre-
sent state.”’ Sermons on Several Subjects, by the late Rev. W. Paley, D.D.
p. 96.

*.
[Seite 49]

Among warm-blood animals, the egg, especially al the fourth and fifth
day of incubation, if placed under a simple microscope, such as the Lyone-
tian, is most proper to demonstrate the circulation.

Among frogs, the most proper is the equuleus of Lieberkühn, described
in the Mem. de l’Acad. de Berlin, 1745.

*.
[Seite 50]

For the various opinions respecting the number and differences of
the arterial coats consult among others Vinc. Malacarne Della Osservat. in
Chirurg
Turin. T. 11. p. 103.

†.
[Seite 50]

Fr. Ruysch, Respons. ad ep. problematicam, iii. Also his Thesaur. Anat.
iv. tab. 3.

‡.
[Seite 50]

B.S. Albinus, Annot. Academ. L. iv. tab. 5. fig. 1.

*.
[Seite 51]

See also J. Theod. van der Kemp, De Vita. Edinb. 1782, 8 vo. p. 51.

†.
[Seite 51]

This is remarkably observable in the adult stag, by comparing the areae
of the external carotid and its branches, during the spring, before the horns
have attained their full growth, but are still covered with their downy inte-
guments, (called in our language, der Bast) with such as they are after this
covering has fallen off.

‡.
[Seite 51]

Ant. Scarpa Sull’ Aneurisma. Pav. 1804, fol. cap. 4.

*.
[Seite 53]

W. Cowper’s Myotomia Reformata. (Postb.) Lond. 1724, Fol. Max.
Tab. xxxvi–xl.

†.
[Seite 53]

Casp. Fr. Wolff on the origin of the large coronary vein, in the Act.
Acad scient. Petropol.
1777. P. i.

Petr. Tabarrani on the same subject, in the Atti di Siena. Vol. vi.

*.
[Seite 54]

Respecting these openings consult among others J. Abernethy, in the
Philos Trans. 1798, p. 103.

†.
[Seite 54]

James Penada, in the Memorie Della Societa Italiana. T. xi. p, 555.

‡.
[Seite 54]

Consult Achill. Meig’s Specimen ii. Observationum Botanicarum, &c.
Basil, 1776, 4to. p. 12. sq.

*.
[Seite 55]

Eustachius. Tab. viii. fig. 6. – tab. xvi. fig. 3. Santorini. Tab. Posth.
ix. fig. 1.

†.
[Seite 55]

Eustachius. Tab. xvi. fig. 6.

‡.
[Seite 55]

Eustachius. Tab xvi. fig. 4.

§.
[Seite 55]

Eustachius. Tab. xvi. fig. 5. Morgagni. Advers. Anat. i. Tab. iv. fig.
3. Santorini, l. c.

ǁ.
[Seite 55]

Consult Hnnter, who treats very minutely of the mechanism of these
valves in his work On the Blood, &c. p. 159.

**.
[Seite 55]

Leop. M.A. Caldani, Memorie lette nell’ Acad. di Padova, 1814.
p. 67.

*.
[Seite 56]

Casp. F. Wolff, in the Act. Acad. Scientiar. Petropol. for the year 1780,
sq. especially 1781, P. i. p. 211. sq. on the cartilaginous texture of the heart,
or of the cartilagineo-osseous fibres, and their distribution at the basis of
the heart.

†.
[Seite 56]

Scarpa’s Tabulae Neurologicae ad Illust. Hist. Anat. Cardiac. Nervor.
Tab. iii. iv. v. vi.

‡.
[Seite 56]

Ruysch. Thesaur. Anat. iv. Tab. iii. fig. 1, 2.

§.
[Seite 56]

Brandis has proposed an ingenious hypothesis to explain the use of
so great an apparatus of coronary vessels. Versuch über die Lebenskraft,
p. 84.

ǁ.
[Seite 56]

Haller. Elementa Physiol. T. i. tab. 1.

Nicholls in the Philos. Trans. Vol. lii. P. 1. p. 272.

**.
[Seite 56]

Littre in the Hist, de l’Academie des Sc. de Paris, 1782, p. 37. Baillie, in
the Transactions of a Society for the Improvement of Medical and Chirurgi-
cal Knowledge.
T. i. p. 91.

*.
[Seite 57]

Consul Ant. Portal’s Memoires sur la Nature & la Traitement de plu-
sieurs Maladies.
T. ii. 1800. p. 281.

*.
[Seite 58]

My observations differ but little from those made by Heberden in Eng-
land. Med. Trans. vol. ii. p. 21, et seq.

†.
[Seite 58]

J.H. Schonheyder De Resolutione et Impotentia motus Muscularis. Hafn.
1768, p. 15. With which work compare the observations of F. Gabr. Sul-
zer in the Naturgesch. des Hamsters, p. 169.

*.
[Seite 59]

Stenon in the Act. Haffniens. T. ii. p. 142.

Sometimes, though rarely, it happens that the right portion of the heart,
oppressed with too much blood, becomes, contrary to what usually takes
place, paralyzed before the left. This I have more than once observed on
opening living mammalia, particularly rabbits.

†.
[Seite 59]

J.N. Weiss De Dextro Cordis Ventriculo post mortem Ampliori. Altorf.
1767, 4to.

‡.
[Seite 59]

Ant. Chaum. Sabatier, In Vivis Animalibus Ventriculorum Cordis eadem
Capacitas.
Paris, 1772, 4to.

§.
[Seite 59]

Sam. Aurivilius, De Vasorum Pulmonal & Cavitat. Cordis inaequali Am-
plitudine.
Gotting. 1750, 4to.

*.
[Seite 61]

The experiments of Hales, in which the blood was received into very
long glass tubes fixed to the arteries of living animals, and measured with
respect to the length of its projection, are indeed beautiful, like every thing
done by this philosopher, who was by nature calculated for such disquisi-
tions. But if the force of the heart is to be estimated in this way, we must
take into account the pressure of the column of blood contained in the tube
and gravitating upon the left ventricle. The result of Hales’ calculations was,
that the blood being projected from the human carotid seven feet and a half,
and the surface of the left ventricle being fifteen square inches, a column of
blood, weighing 51 lb. 5oz. was incumbent upon the ventricle and overcome
by its systole. Statical Essays, vol. ii. p. 40. London, 1733, 8vo.

†.
[Seite 61]

Thus, to say nothing of the phenomena so frequently observed in the cold
blooded amphibia and fishes, I lately found the heart of the chick beat for
twelve hours, in an egg, on the fourth day of incubation.

‡.
[Seite 61]

Consult Fontana, who treats of this prerogative of the heart minutely in
his Ricerche sopra la Fisica animale, and limits it too much. Haller answered
him in the Literary Index of Gottingen.

*.
[Seite 62]

Haller on the motion of the heart from stimulus, in the Comment. Soc.
Scient. Gottingens.
Tom. i.

G.E. Remus, Experimenta circa, circulat. sanguin. instituta. Gotting, 1752,
p. 14, 4to.

†.
[Seite 62]

On this dispute cousult R. Forster’s Quaestion. select. Physiol. Ludg. Bat.
1774, 4to.

J.B.J. Behrend’s Dissert, qua demonstratur cor nervis carere. Mogunt.
1792, 4to. and on the other side, J. Munnik’s Observationes variae, Groning.
1805, 4to Lucae, l. c. p. 37. p. ii.

‡.
[Seite 62]

And how much more so when the heart is diseased, is shown in Caleb
Hill Parry’s Inquiry into the Symptoms and Causes of the Syncope Anginosa,
commonly called Angina Pectoris.
p. 114, Bath. 1799, 8vo. p. 114.

*.
[Seite 63]

Andr. Wilson’s Inquiry into the moving powers employed in the Circula-
tion of the blood.
Lond. 1774, 8vo. p. 35, sq.

†.
[Seite 63]

Sec. v.c. C.W. Curtius, De monstro humane cum infante gemello, Ludg.
Bat. 1762, 4to, p. 39. W. Cooper, in the Philos. Transac. vol. lxv. p. 316.
Haller’s Opera Minora. T. iii. p. 33, C. Chr. Klein’s Descriptio Monstrorum
quorundam,
Stuttg. 1793, 4to.

‡.
[Seite 63]

Walter Verschuir, De arteriar. et venar. vi irritabili; ejusque in vasis ex-
cessu; et inde oriunda sanguinis directione abnormi.
Groning. 1766, 4to.

Rich. Dennison, Diss. arterias omnes et venarum partem irritabilitate prae-
ditas esse.
Edinb. 1775, 8vo.

Chr. Kramp, De vi vitali arteiarum. Argent. 1785, 8vo.

*.
[Seite 64]

Observe for instance, in Walter’s Tabulae nervor. thorac. et abdominis,
the right hepatic, Tab. ii. O. Tab. iii. l. – the splenic, tab. ii. P. Tab. iii. m.
tab. iv. o. – The superior mesenteric, Tab. ii Q. Tab. iii. s. – the inferior me-
senteric, Tab. ii. T. – and many others. Compare Soemmerring de c. h.
fabrica
. T. iv. p. 362.

†.
[Seite 64]

Haller De Nervor. in arterias imperio. Gotting. 1744, 4to. Lucae, l. c.

‡.
[Seite 64]

Th. Kirkland’s Inquiry into the present state of Medical Surgery. London,
1783, 8vo. vol. i. p. 306, sq.

*.
[Seite 65]

Physiological Essays, containing an inquiry into the causes which promote
the circulation of the fluids in the very small vessels of animals,
&c. &c. Second
Edition, Edinb. 1761, 12mo.

H. v. d. Bosch, über das Muskelvermögen der Haargefüssgen. Monast.
1786, 8vo.

†.
[Seite 65]

What is commonly, but improperly, called the venous pulsation, observa-
ble on opening living animals and in some morbid affections, and also under
a violent effort, does not correspond with the action of the heart, but with
respiration; since if an expiration is unusually deep and lenthgened, and
the reflux of the blood to the lungs thus impeded, the juglar vein swells as
far as the brain, the subclavian as far as the basilic, and the inferior cava as
far as the crural.

*.
[Seite 66]

G. E. Stahl, De vena portae porta malorum. Halae. 1698, 4to.

†.
[Seite 66]

Lister, De humoribus, p. 25.

*.
[Seite 67]

A Treatise on the Blood, &c. by John Hunter, p. 146. Note.

†.
[Seite 67]

The Muscular Motions of the Human Body, by John Barclay, M.D.
p. 567.

*.
[Seite 68]

Edinburgh Medical and Surgical Journal, 1815.

†.
[Seite 68]

An Inquiry into the Causes of the Motion of the Blood, by James Carson,
M.D. 1815.

*.
[Seite 71]

Anatomie Generale, T. ii.

†.
[Seite 71]

Animal Chemistry, p. 25.

*.
[Seite 72]

An Experimental Inquiry into the Nature, Causes, and Varieties of the
Arterial Pulse,
&c. by Caleb Hillier Parry, M.D. F.R.S. 1816.

*.
[Seite 73]

Soemmerring und Reisseisen, über die Structur, die Verrichtung und den
Gebbrauch der Lungen. Zwey Preischriften.
Berol, 1808. 8vo.

†.
[Seite 73]

Respecting all the organs concerned in respiration, consult Corn. J. Van
Der Bosch’s Anatomia Systematis Respirationi Inservientis Pathologica. Har-
lem, 1801, 4to. p. 1–44.

*.
[Seite 74]

Keil indulging his luxuriant iatro-mathematical genius, assigned more
than 1744,000,000 cells to each lung.

†.
[Seite 74]

Lieberkühn, with equal exaggeration, made the surface of the cells equal
to 1500 square feet.

‡.
[Seite 74]

Eustachius. Tab. xxvii. fig. 13.

*.
[Seite 75]

Mascagni. Histor. vasor. lymphatic. Tab. xx.

†.
[Seite 75]

Ibid. Tab. xxi.

‡.
[Seite 75]

Consult Portal in the Mém. de l’Acad. des Scienc. de Paris. 1780

§.
[Seite 75]

J.G. Amstein (Praes. Oetinger) De usu et actione musculor. intercostal.
[Seite 76] Tubing. 1769, 4to. Theod. Fr. Trendelenburg, Jun. De sterni costarumque
in respiratione vera genuinaque motus ratione.
Gotting, 1779, 4to. Bordenave
and Sabatier, in the Mém. de l’Acad. des Scienc. de Paris, 1778.

*.
[Seite 76]

Haller, Icon. Anat. fascic. 1, Tab. 1.

B.S. Albinus. Tab. musculor. Tab. xiv. fig. 5, 6, 7.

J.G. Röderer, De arcubus tendineis muscul. progr. 1. Gotting 1760.
4to.

Santorini, Tab. Posth. x. fig. 1.

†.
[Seite 76]

De Anatomicis Administrationibus, L. viii. cap. 8. The whole book is
full of experients on respiration.

‡.
[Seite 76]

Ephr. Krüger. De nervo phrenico. Lips. 1759, reprinted in Sandifort’s
Thesaurus Tom. iii.

Walter’s Tab. nervor. thorac. et abdominis, Tab. 1, fig. 1, n. 1.

*.
[Seite 77]

The antiquity of the notion that air is the pabulum vitae, is seen in the
book de Flatibus, usually ascribed to Hippocrates. The author regards the
aliment as threefold – victuals, drink, and air: but the latter he calls vital,
because we cannot dispense with a perpetual supply of it, without danger to
life

†.
[Seite 77]

Consult Harvey’s Dispute upon the necessary renovation of the aerial
uccus alibilis, with the celebrated Astronomical Professor, J. Greaves,
[Seite 78] in the latter’s Description of the Pyramids of Egypt, p. 101, sq. Lond. 1646,
8vo. Also Edm. Halley’s immortal popular Discourse concerning the Means
of furnishing Air at the bottom of the Sea in any ordinary Depth.
Phil. Trans,
vol. xxix. No. 349, p. 492, sq.

*.
[Seite 78]

Fr. Stromeyer, Grundriss der Theoretischen Chemie, P. ii. p 619.

†.
[Seite 78]

Consult, for instance, Abilgaard in the Nordisch. Archiv. fur Naturkunde,
&c. T. 1. P. i. and ii.

‡.
[Seite 78]

Consult, besides, Priestley and others, especially C. II. Peaff, ib. P. iv.
P. ii.

§.
[Seite 78]

To discover how frequently an animal could breathe the same
[Seite 79] portion of air, I took three dogs equal in size and strength; and to the tra-
chea of the first, by means of a tube, I tied a bladder, containing about 20 cu-
bic inches of oxygen gas. He died in 14 minutes.

With the second, the bladder was filled with atmospheric air. He died in
6 minutes.

With the third, I employed the carbonized air expired by the second dog.
He died in 4 minutes.

Upon afterwards examining the air of the bladder, it gave the common
signs of carbonic acid gas. The instruments which 1 employed are described
and illustrated by a plate in the Medic. Biblioth. Vol. 1. p. 174. et. seq.
tab. 1.

*.
[Seite 79]

J.A. De Luc. Idées sur la Météorologie, tom. ii. p. 67. 229.

†.
[Seite 79]

Rob. Menzies, De Respiratione. Edinb. 1790, 8vo.

H. G. Rouppe on the same subject. Lugd. Batav. 1791, 4to.

J. Bostock’s Versuch über das Athemolen. übers. von. A.F. Nolde. Erf.
1809. 8vo.

‡.
[Seite 79]

J. Andr. Scherer. Beweis dass. J. Mayow, vor 100. Jahren den Grund Zur
Antiphlogistischen Chemie und Physiologie gelegt hat,
p. 104. Edm. Godwyn’s
Connexion of Life with Respiration. Lond. 1788, 8vo. J. Hunter, On the
Blood,
p. 68. J.A. Albers in the Beyträgen zur Anat. und Physiolog. der
Thiere.
P. 1, p. 108.

*.
[Seite 80]

See J. Brugnatelli’s Elementi di Chimica. T. 1. p. 155. T. Fr. Gmelin,
De Acidorum origine ex aëre vitali adhuc dubia in the Comment. Soc. Reg. Sc.
Gotting.
T. xiii.

*.
[Seite 81]

It bears the epithet Hookian, because it was most adorned by Rob.
Hooke. See Th. Sprat’s History of the Royal Society. Lon. 1667, 4to. p. 232.
But it was before instituted and very much praised for its beauty by Vesali-
us. De c. h. Fabrica. p. 824.

†.
[Seite 81]

Wm. Harvey De circulat. sanguin. ad T. Riolan, p. 258. Glasgov. 1751,
12mo. and especially his Exerc. de genere Animalium, p. 263. London, 1651,
4to.

‡.
[Seite 81]

See Theod. G. Aug. Roose Uber das Ersticken neugebohrner Kinder. in his
Physiologisch. Untersuchugen. Brunsw. 1796, 8vo. J.D. Herholdt De vita im-
primis foetus humani, ejusque morte sub partu,
Havn. 1802, 8vo.

§.
[Seite 81]

Consult, for example, Petr. T. Daoustenc De Respiratione. Lugd. 1743, 4to.
p. 34, sq. Rob. Whytt on the Vital and other involuntary Motions of Animals, p.
222. Edinb. 1751, 8vo.

*.
[Seite 85]

On Respiration.

†.
[Seite 85]

Toxicologie Generale.

‡.
[Seite 85]

Annals of Medicine and Surgery, vol. i. p. 155.

§.
[Seite 85]

[Fußnotentext auf Seite 85 und Fußnotenverweis auf Seite 86]Philos. Trans. 1808. and 1809.

*.
[Seite 86]

Animal Chemistry.

†.
[Seite 86]

Thomson’s Annals of Philosophy, 1814.
Dissert. Inaugur. &c. Edinb. 1814.

*.
[Seite 87]

Th. Young in The Philos. Trans. 1800 P. 1.

†.
[Seite 87]

Jan. Marg. Busch De Mechanismo Organi vocis hujusque Functione.
Groning. 1770. 4to.

‡.
[Seite 87]

Soemmerring’s Icones Organorum Gustus et Vocis. Francof. 1808. fol.

§.
[Seite 87]

B.S. Albinus’ Tab. Muscul. Tab. X. fig. 1–15. Tab. XI. fig. 45–48.
Tab. XII. fig. 1–7.

*.
[Seite 88]

Kratzenstein viewed the glottis and larynx as a kind of drum, with its
head bisected. Tentamen de Natura et Charactere Sonorum Litterarum Vo-
calium.
Pretop. 1781. 4to. I would, in some sense, compare it to an Eolian
harp, particularly one of the description found by Labillardiére in Amboyna.
Voyage à la Recherche de la Perouse. T. i. p. 326.

†.
[Seite 88]

See some experiments made at Gottingen with the view of settling
this controversy, in J.G. Runge’s Dissertation De Voce Ejusque Or-
[Seite 89] ganis.
L.B. 1753. 4to. Also consult Jos. Ballanti, in the Commentar. In-
stituti Bonon.
T. vi. Vicq-d’Azyr in the Mem. de l’Acad. des. Sc. de Paris.
A. 1779.

*.
[Seite 89]

Respecting this celebrated experiment, anciently made by Galen, con-
sult among others W. Courten, in the Philos Trans. N. 335. Morgagni.
Ep. Anatom. xii. No. 20. P.P. Molinelli, in the Comment. Institut. Bonon.
Tom. iii. J. Haighton, in the Memoirs of the Medical Society of London.
T. iii.

†.
[Seite 89]

The larynx, even among the most ferocious people, is capable of imi-
tating the sounds of animals.

Consult Nic. Wisten, Noord en oost – Tartarye ed. 2. Amst 1705. vol. 1.
p. 165, respecting the southern inhabitants of New Guinea, called Papus.
And. J. Adair, in his History of the American Indians, p. 309, respecting the
Chotkah tribe of North America.

*.
[Seite 90]

I have in my hands the testimony of most respectable travellers, in re-
gard, for instance, to the inhabitants of Ethiopia, Greenland, Canada, Cali-
fornia, Kamtschatka, &c. and therefore wonder at the assertion of Rous-
seau, that singing is not natural to man. Dictionn. de Musique T. i. p. 170,
Genev. 1781. 12mo.

†.
[Seite 90]

See Rich. Payne Knight’s Analytical Essay on the Greek Alphabet.
Lond, 1791, 4to. p. 3.

*.
[Seite 91]

Consult F. Mercur. ab. Helmont’s Alphabeti vere Naturalis Hebraici
Delineatio.
Sulzbac. 1657. 12mo.

Joach. Jungii Doxascopiae Physicae Minores (1662) 4to. Append. Sec-
tion i. P. ii. fol. G. ii. g. 3.

J. Wallis’ Grammatica Linguae Anglicanae, cui praefigitur de loquela s. sono-
rum omnium loquelarium formatione tract, grammatico-physicus.
Ed. 6. Lond.
1765. 8vo.

Gottl. Conr. Chr. Storr. De Formatione Loquelae. Tubing. 1781. 4to.

†.
[Seite 91]

K.G. Anton, Uber Sprache in Rücksicht auf Geschichte der Menschheit.
Görlitz. 1799. 8vo.

Er. Darwin’s Temple of Nature. Addit. Notes, p. 112.

‡.
[Seite 91]

His Surdus Loquens. Amst. 1692. 8vo. With the Dissert. de Loquela.
lb. 1700.

§.
[Seite 91]

Respecting their formation, consult Chr. Theoph. Kratzenstein’s Tenta-
men,
recommended above.

*.
[Seite 92]

Fr. Lupichius De Risu, Basil, 1738. 4to. Traité des Causes Physi-
ques et Morales du rire.
Amst. 1788. 8vo.

†.
[Seite 92]

J. Melch. Fr. Albrecht (Praes. Haller.) Experimenta in vivis Animalibus
circa tussis organa exploranda instituta.
Gotting. 1751. 4to.

‡.
[Seite 92]

Marc. Beat. L.J. Porta De Sternutatione. Basil, 1755. 4to.

*.
[Seite 93]

C.J. Sig. Thiel De Singulter. Gotting. 1761. 4to.

†.
[Seite 93]

J.F. Schreiber De Fletu. L.B. 1723. 4to.

‡.
[Seite 93]

Dav.c. Imm Berdot. De suspirio. Basil. 1756. 4to.

§.
[Seite 93]

Just. Godofr. Günz (Praeside Walthero) De Oscitatione. Lips. 1738. 4to.

*.
[Seite 94]

Experiences sur le Principe de la Vie. Par M. Le Gallois.

†.
[Seite 94]

These observations of M. Majendie’s are contradictory to those of M.
Le Gallois.

*.
[Seite 95]

Precis Elémaentaire de Physiologie, par. F. Majendie. T. 1. p. 216. seq.

*.
[Seite 96]

W.B. Johnson’s History of Animal Chemistry. Vol. iii. p. 79.

†.
[Seite 96]

The torpid state of some animal, during winter, is of course an ex-
ception to this. Most of the functions cease or languish considerably, and
the animal heat is reduced nearly to coolness. This well-known circum-
stance prevents me from acceding to the opinion of the very acute J. Hunter,
– that the animals which we call warm blooded, should rather be called
animals of a permanent heat under all temperatures. On the Blood, p 15.

‡.
[Seite 96]

J.B. Van Mons in the Journal de Physique. T. lxviii. 1809, p. 121.

*.
[Seite 97]

Philos. Trans. vol. i. P. ii. 1758. Arn. Dantze had previously made the
observation in regard to brutes. Exper. Calorem Animalem Spectantia. Ludg.
Bat. 1754, 4to. Also Benjamin Franklin’s Experiments and Observations on
Electricity.
Lond. 1769, 4to. p. 365.

†.
[Seite 97]

Duhamel and Tillet, in the Mem. de l’Acad. des Scienc. de Paris, 1704.

Blagden and Dobson. Philos. Trans. 1765.

‡.
[Seite 97]

The heat of the weather, even in Europe, occasionally exceeds our natu-
ral temperature. This was the case on the third of Aug. 1783, at noon
when I was on the Lucern Alps, in company with the excellent Schnyder de
Wirtensee. The thermometer in the shade stood above 100° Fahr. and when
applied to the body, invariably sunk to 97°.

*.
[Seite 98]

See Lichtenberg’s Animadversions upon this part of Crawford’s Theory,
in his notes to Erxleben’s Anfangsgr. der Naturlehre. p. 447. ed. vi.

†.
[Seite 98]

Hence the constant coldness of those wretched beings who labour under
the blue disease, which arises from a mal-conformation of the heart. Some-
times the septa of the heart are imperfect, sometimes the aorta arises with
the pulmonary artery from the right ventricle, as in the tortoise. In such
instances, the chemical changes cannot take place in the lungs. Among
innumerable instances of this lamentable disease, suffice it to quote J. Aber-
nethy’s Surgical and Physiological Essays. P. ii. p. 158, and Fr. Tieaemann.
Zoologic. T. i p. 177.

‡.
[Seite 98]

I have formerly treated of the influence of the nervous system upon ani-
mal heat, in my Specimen Physiologiae Comparatae Inter Animantia Calidi &
Frigidi Sanguinis,
p. 23.

See the same confirmed by many arguments in Magn. Ström’s Theoria In-
flammationis Doctrinae de Calore Animali Superstructa.
Havn. 1795, 8vo. p.
30, sq. and by the much lamented Roose, in the Journal der Erfindungen, &c.
T. v. p. 17.

Consult also Dupuytrem in the Analyse des Travaux de l’Institut. 1807,
p. 16.

*.
[Seite 99]

See Crawford in the Philos. Trans. vol. lxxi. p. ii.

†.
[Seite 99]

G. Pickel’s Experimenta Physico-Medica de Electricitate et Calore Ani-
mali. Wirceb.
1788, 8vo. p. 91. sq.

‡.
[Seite 99]

C. Ferd. Becker De Effectibus Caloris et Frigoris Externi in c. h. Gott.
1802, 4to. and Wm. Fr. Baur On the same subject, ib. eod. (both honoured
with the Royal Prize.
) Mich. Skjelderup. Dissert. Sistens Vim Frigoris in-
citantem.
Hafn. 1803, 8vo.

§.
[Seite 99]

J. Chr. Goeschen. (Praes. Ph. Fr. Meckel) Pulmonum cum Cute
[Seite 100] Commercium.
Hal. 1789. 8vo. But especially J.D. Brandis. Pathologie
Hamb. 1808, p. 316, sq.

*.
[Seite 100]

See, for instance, Tacconi in the Comment. Instit. Bononiens. Vol. vi.
p. 74.

*.
[Seite 103]

Philos. Trans. 1814.

†.
[Seite 103]

Philos. Trans. 1812.

‡.
[Seite 103]

Crawford on Animal Heat. P. 387, sq.

*.
[Seite 104]

L. c. p. 388.

†.
[Seite 104]

Dr. Davy, Philos. Trans. 1814.

*.
[Seite 105]

Al. Monro Primus. Oratio de Cuticula Humana. Opera. English Edi-
tion. Edinb. 1781, 4to. p. 54, sq.

†.
[Seite 105]

Among others, consult J. Mitchell, in the Philos. Trans. Vol. xliii p.
111.

*.
[Seite 106]

Abr. Kaau, Perspiratio Dicta. Hippocrati, p. 7.

Lieberkuhn, De Fabrica Villor. Intestin. Tenuium, p. 16.

Cruikshank’s Expts. on the Insensible Perspiration, p. 5.

Rudolph, Reisebemerkungen. T. i. p. 29, 140.

Jens. W. Neergaard, Vergleichende Anat. der Verdauungswerkzeuge, p. 21,
& alibi.

†.
[Seite 106]

The very dense epidermis of some immense animals consists of vertical
fibres, which, in arrangement, somewhat resemble the structure of the
Boletus igniarius. Its internal surface is porous and penetrated by the fi-
laments, in appearance silken, of the subjacent corium. This is remarka-
bly exemplified in a preparation now before me, taken from the skin of the
balaena mysticetus. The human cuticle, in certain diseased states, exhibits
the same appearance as in the Englishman called the Porcupine Man, who
laboured under a cuticular complaint which he transmitted to his children
and grand-children. Vide W.G. Tilesius’ Beschreibung und Abbildung der
beiden sogenannten Stachelschwein-Menschen
(Porcupine Men.) Altenb. 1802,
fol.

The innumerable polyedrical papillae and horny warts which I witnessed
upon every part of the skin of these brothers, excepting the head, the palms
of the hands and the soles of the feet, bore some resemblance to the skin of
the elephant, especially about the vertex and forehead of the animal.

[Seite 107]

Similar also are corns, and the brawny cuticle of the feet, in those who
walk barefooted. Vide Carlisle on the Production and Nature of Corns in
the Med. Facts and Observations. Vol. vii. p. 29.

*.
[Seite 107]

W. Hunter, in the Med. Observations and Inquiries, vol. ii. p. 52, sq. tab.
i. fig. 1, 2. The conjecture of this eminent man, that the fibrils excrete
the perspirable matter, is, I think, improbable.

†.
[Seite 107]

Hence I have found the Epidermis of Albinos separate easily by the
heat of the sun; whereas in negroes, it scarcely does so on the application
of a blister. C.F. Mitchell, l. c. p. 108.

*.
[Seite 108]

B.S. Albinus De sede & Causa Coloris Aethiopum et Caeteror. Homi-
num.
Lugd. Batav. 1737, 4to. fig. 1.

Sam. Th. Soemmerring Uber die körperl. Verschiedenh. des Negers vom
Europäer.
Ed. 2. p. 46. sq.

Some even of the moderns have assigned many laminae, and even diffe-
rent kinds of laminae, to the reticulum; as Lieutaud in his Estais Anato-
miques,
p. 103. ed. 1766; and Cruikshank, l. c. p. 43, 99.

Others make it organic. Vide Mich, Skjelderup, l. c. p. 93.

†.
[Seite 108]

Jo. Nic. Pechlin, De Habitu et Colore Aethiopum, qui Vulgo et Nigritae.
L. Kilon. 1677, 8vo. Camper’s oration on the same subject will be found in
bis kleiner Schriften Vol. i. P. 1. p. 24–49.

*.
[Seite 109]

I have given this opinion at some length in my work, De Gen. Human.
Varietate Nativa,
p. 122, sq. ed. 3. Some eminent chemists accord with me,
among whom suffice it to mention the celebrated Davy, in the Journals of the
Royal Institution,
vol. ii. p. 30. ‘“In the rete mucosum of the African, the
carbon becomes the predominant principle; hence the blackness of the ne-
gro.”’ W.B. Johnson, l. c. vol. ii. p. 229.

*.
[Seite 110]

Chr. Gottl. Ludwig, De Humore Cutem Inungente. Lips. 1748, 4to.

†.
[Seite 110]

Lyonet, Lettre à M. Le Cat. p. 12.

‡.
[Seite 110]

Jo. Ph. Withoff, De pilo Humano, Duisb. 1750, 4to. Compare the Com-
mentar. Socient. Gotting.
Vol. ii.

Job. Baster, Verhandel. der Maatsch. te Haarlem, T. xiv. p. 382

§.
[Seite 110]

De Generis Human. Variet. Nativ. p. 29.

*.
[Seite 111]

Galen, Ars Medicinalis, p. 211–235. M. Ant. Ulm. Uterus Muliebris
p. 128, et alibi. Lavater, Fragmente, T. iv. p. 112.

†.
[Seite 111]

I suspect that the bulb is intended for support rather than for nourish-
ment, from this circumstance, that the locks of hairs sometimes found in
melicera and steatomata of the omentum and ovarium, some of which I have
[Seite 112] now before me, are usually destitute of bulbs, because they are not fixed, but
lie naked in the honey-like fatty matter.

*.
[Seite 112]

Duverney, Ouvres Anatomiques, Vol. i. Tab. xvi. fig. 7, 9–14. Tab. xvij.
fig. 3, sq.

†.
[Seite 112]

B.S. Albinus, Annotat. Academ. L. vj. Tab. iij. fig. 45.

‡.
[Seite 112]

Hence the danger of contagion from hairs, to which miasmata very tena-
ciously adhere for a great length of time. Vide Cartwright’s Journal of
Transactions on the Coast of Labrador,
vol. i. p. 273. vol. ii. p. 424.

§.
[Seite 112]

Ars Sanctor. Sanctorii, De Statica Medicina Aphorismor. sanctionibus vij.
Comprehensa.
Venet. 1634, 16to.

ǁ.
[Seite 112]

C. de Milly and Lavoisier, Memoires l’Acad. des Sc. de Paris,
[Seite 113] 1777, p. 221, sq. 360, sq. J. Ingenhouz, Expts. upon Vegetables. Lond. 1779,
8vo. p. 132, sq. J.H. Voight. Versuch einer neuen Theorie des Fevers, p. 157,
sq.

*.
[Seite 113]

W. Basche, on the Morbid Effects of Carbonic Acid Gaz, on Healthy Ani-
mals,
Philadel. 1794, 8vo. p. 46.

†.
[Seite 113]

Abernethy, l. c.

‡.
[Seite 113]

Fr. L. Andr. Koeler, De Odore per Cutem spirante in statu sano ac mor-
boso,
Gotting. 1794, 4to.

§.
[Seite 113]

The balance employed by Sanctorius, to estimate the loss of perspired
matter, is described in his Comm. in Primam Fen Primi L. Canon. Avicennae.
Venet. 1646, 4to. p. 781.

Another much more simple and better adapted for the purpose, is describ-
ed by Jo. Andr. Segner, de Libra, qua sui quisque corporis pondus explorare
posset,
Gotting. 1740, 4to. J.A. Klindworth, an excellent Gottingen instru-
ment-maker, at my instigation, altered this, and rendered it more convenient
and accurate.

*.
[Seite 114]

Lavosier and Seguin (Memoires de l’Academie des Sciences, 1790, p. 610)
enclosed the body in a silk bag varnished with elastic gum, having a small
opening carefully cemented around the mouth, so that by weighing the body
previously and subsequently to the experiment, they were able to ascertain
exactly what had been lost by vapour, and by subtracting from this loss the
weight of the perspired contents of the bag, they also ascertained how much
of this had passed off by the lungs. From repeated trials they found the
mean pulmonary discharge in twenty-four hours amounted to 15 oz. and the
cutaneous to 1 lb. 14 oz. The quantity of carbon separated by the lungs
ought however to have been taken into the acconnt. If it amounts to 11 oz.
in twenty-four, which I cannot believe it does, there will be but 4 oz. of pul-
monary exhalation.

†.
[Seite 114]

Cruikshanks on Insensible Perspiration, and Ellis’s Further inquiry on the
Changes produced in Atmospheric Air,
&c.

‡.
[Seite 114]

Medical Reports, &c.

§.
[Seite 114]

Rollo, On Diabetes.

ǁ.
[Seite 114]

La Mediciné eclairée, &c. T. 3.

*.
[Seite 115]

Edinburgh Med. and Surg. Journal, vol. i.

†.
[Seite 115]

Watson’s Chemica Essays. iii. 101.

‡.
[Seite 115]

Medical Facts and Experiments.

‡.
[Seite 115]

Medical Facts and Experiments.

*.
[Seite 116]

Eustachii, tab. xviii. fig. 2.

†.
[Seite 116]

Diss. debasi eucephali. Gotting. 1778, 4to. p. 17. Also his work, already
quoted, upon the anatomy of the negro, 59, sq.

J Gotter. Ebel’s Observationes neurologicae ex anatome comparata. Traj.
ad.Viadr. 1788, 8vo.

*.
[Seite 117]

Eustachii, tab. xvii. xviii.

Halleri Icones anat. fasc. vi. tab. i. ii. iii.

Santorini, tab. posth. ii. iii.

†.
[Seite 117]

J. Ladmiral’s Icones durae matris in concava et convexa superficie visae.
Amst. 1738, fasc. i. ii. 4to.

‡.
[Seite 117]

In the skulls of some mammalia, a remarkable lamina of bone pe-
netrates a duplicature of the tentorium, and supports it. Cheselden (Anat.
of the bones,
c. 8.) supposes this bony tentorium to exist in ferae only; but
it is found in the equine genus, the cercopithecus paniscus, the delphinus
phocoena, &c. Its use is uncertain: that which is generally ascribed to it
(for instance, by Laur. Nihell de cerebro. Edinb. 1780, p. 4) of supporting
the cerebellum in those mammalia which leap considerably, is improbable,
because we find it in animals also of slow motion, as the bear, and not in the
ibex, which moves with the greatest velocity.

§.
[Seite 117]

Vieussen’s Neurograph, univaersal, tab. xvii. fig. 1

Duverney’s Oeuvres anatom. vol. i. tab. iv.

[Seite 118]

Haller’s icones anat. fasc. i. tab. vi.

Walter De morbis peritonaei et apoplexia. Berol. 1785, 4to. tab. iii. iv.

Vicq. d’Azyr’s Planehes Anatomiques. xxxii. et xxxv.

*.
[Seite 118]

Ruyschii Respons. ad ep. problemat. nonam. Amst. 1670, tab. x.

†.
[Seite 118]

B.S. Albini Annot. acad. L. 1. tab. ii. fig. 1. 5.

‡.
[Seite 118]

S. Th. Sömmerring über das Organ der Seele. Region. 1796, 4to.
tab. i. ii.

§.
[Seite 118]

The importance of this plexus is shewn in the dissection of maniacs, in
whom it alone is very frequently found diseased.

*.
[Seite 119]

De basi encephali, p. 13.

Compare Gennari De peculiari structura cerebri Parmae, 1782, 8vo. tab.
ii. iii.

†.
[Seite 119]

Malpighi De cerebri cortice c. rel. de viseerum structura Exercit. Lond.
1699, 12mo.

Ruysch De cerebri corticali substantia ep. problemat. xii. Amst. 1699.
4 to.

Chr. Frid. Ludwig. De cinerea cerebri substantia. Lips. 1799, 4to.

‡.
[Seite 119]

Sömmerring De habitu vasorum cerebri in Denkschriften der Acad. der
Wiss. zu München.
1808, tab. i.

§.
[Seite 119]

B.S. Albini Annat. Acad. L. 1. tab. ii. fig. 4. 5.

ǁ.
[Seite 119]

Consult Metzger’s Animadversiones ad doctrinam nervorum. Regiomont
1783, 4to.

**.
[Seite 119]

T. Dan Schlichting first accurately described this phenomenon in the
Commerc. litter. Noric. 1744, p. 409, sq. and more largely in the Mém. pre-
sentés à l’Acad. des Sc. de Paris,
T. 1. p. 113.

[Seite 120]

Haller discovered the cause of it by numerous dissections of living ani-
mals. See his pupil, J. Dit. Wolstorf’s Experimenta circa motum cerebri,
cerebelli,
&c. Gotting. 1753.

Consult also after F. de la Mure, Larry’s Dissertations on the same point
in the Mem. Presents, T. iii. p. 277, sq. 344, sq. Also Portal on a similar
motion, observable in the spinal marrow. Mém. de la Nature de plusiers
Maladies.
T. ii. p. 81.

*.
[Seite 120]

I once enjoyed an opportunity of very distinctly observing this motion
and making some experiments with respect to it, in a young man eighteen
years of age. When not five years old, he had fallen from an eminence and
fractured the frontal bone on the left side of the coronal suture: since which
time, there had been an immense hiatus, covered by merely a soft cicatrix
and the common integuments. The hiatus formed a hollow, deeper during
sleep, and varying according to the state of respiration: very deep if he re-
tained his breath, much more shallow, and even converted into a swelling,
by a long continued expiration. At the bottom of the hollow, I observed a
pulsation synchronous with the pulsation of the arterial system, such as
deceived Petriolus, Vandellus and other adversaries of Haller, confounding
it with that which depends upon respiration. – I may add, that this wound on
the left side of the head, had rendered the right arm and leg paralytic.

†.
[Seite 120]

J.J. Huber De medulla spinali. Gotting. 1741, 4to. The plate is to
be found among Haller’s fascic. i. tab. ii.

Haller’s own plates of the same part are in the same fasciculus, vii. tab.
iv. v.

Monro (filius) On the Nervous System, tab. x. fig. 1.

‡.
[Seite 120]

Consult the Anatomie et Physiologie du systeme Nerveux, &c. par F.J.
Gall et G. Spurzheim. T. 1. Paris, 1810, 4to.

*.
[Seite 121]

Reil De Structura Nervorum, Hal. 1796, fol.

Osiander in the Comm. Soc. Reg. sc. Gotting. T. xvi.

†.
[Seite 121]

Rob. Martin’s oration De Proprietatibus Nervorum Generalioribus, pre-
fixed to his Instit. Neuroligicae.

‡.
[Seite 121]

Haller on the sensible parts of the body in the Comment. Soc. sc. Got-
ting. T. i. and his discourse upon them in the Nov. Comment. Gotting.
T. iii.

Petre Castell’s Experim, quibus constitit varias h. c. partes sentiendi facul-
tate carere.
Gotting. 1753, 4to. And three entire collections on the con-
troversies excited by the Gottingen publications throughout Europe.

Sull’ insensibilitate irritabilita, dissertazioni transportate da J.G.Y. Petrini
Rom. 1755, 4to.

Sulla insensitiva ed irritabilita Halleriana opuscoli raccolti da G.B. Fabri.
Bonon. 1757–59, iv. vol. 4to. And that which Haller himself published
under the title of Mémoires sur la Nature sensible et irritable des Parties du
corps humain.
Lausanne, 1756–59. iv. vol. 12mo.

§.
[Seite 121]

In the great variety and even contradiction of opinion, which, as
we shall presently mention, exists in respect to the feeling of tendons
and other parts when injured, I have always considered negative argu-
[Seite 122] ments of more weight than positive, because nothing is more fallacious
than the ideas of patients as to the seat of internal pains. To say nothing
of cases where amputated parts appear to the patient as still in possession
of feeling, it is well known that some have felt a fixed pain for a great length
of time, in parts where after death nothing uncommon was observable;
and that, on the other hand, in chronic diseases, pain is sometimes not
felt in the diseased part, but in another which is healthy and perhaps
very remote.

We may in this way much more easily explain syphilitic pains, for in-
stance, referred to the bones, than so many contradictory experiments, in
which I have seen the medulla roughly handled without causing the least
uneasiness.

*.
[Seite 122]

I am every day more convinced that much caution and practice
ajid repetition of the same experiment, in many different kinds of ani-
mals, are necessary in establishing the laws of physiology from dis-
sections of living animals. To adduce the example of the supposed
feeling of the medulla, I have found different results in many mam-
malia and birds. Many allowed the medulla to be destroyed without
evincing any symptom of pain; others were convulsed, and cried out
on the approach of the instrument. The latter might be agitated from
the dread of fresh torment, on seeing the knife; and the former, having
suffered great torture, might have been insensible to the less violent irri-
tation of the medulla, although it were endowed with nerves.

*.
[Seite 123]

Lassus has diligently collected the different opinions of writers on this
point. Sur les découvertes faites en Anatomie, p. 299, sq.

†.
[Seite 123]

Compare Mein. Sim. De Pui De homine dextro et sinistro. L.B. 1780,
8vo. p. 107, sq.

‡.
[Seite 123]

v. Gall and Spurzheim, and Osiander. ll. cc.

§.
[Seite 123]

Sömmerring in the Hessischen Beyträgen zur Gelehrsamkeit, P. i. et iv.

F.N. Nöthig. (praes. Sommerring) De decussatione nervorum optic.
Mogunt. 1786, 8vo.

J.F. Ackermann in the Biblioth. Medica, which I published, vol. iii. p. 337.
706.

Hor. Caldani, Opuscula Anat. Patav. 1803, 4to. p. 111.

J. and C. Wenzel. Prodromus eines Werkes über das Hirn. p. 11.

ǁ.
[Seite 123]

Consult Pfeffinger De structura Nervorum. Argent. 1782, 4to.

**.
[Seite 123]

Wm. Battie De Principiis Animalibus. p. 126.

††.
[Seite 123]

Comment. Instituti Bonoinens. T. iii. 1755, p. 282, sq. fig. 1, 2.

The observation of Mollinelli has been abundantly confirmed and further
illustrated by Felix Fontana and Al. Monro: the latter in his work so often
quoted, and the former in his treatise Sur le Vénin de la Viperè. Flor. 1781,
4to. vol. ii.

*.
[Seite 124]

Mém. de l’Acad. des Sc. de Berlin. Vol. ix. 1753.

†.
[Seite 124]

Consult among others who treat professedly of the ganglia, J. Johnstone
in the Med Essays and Observ. Evesham, 1795, 8vo.

J. Gottl. Haase’s Dissertation. Leips. 1772, 4to.

T. Caverhill’s Treatise on Ganglions. Lond. 1772, 8vo.

Ant. Scarpa’s Anatom. Annotat. L. i. De nervor. Gangliis et Plexubus.
Matin. 1722, 4to.

G. Prochaska De structura nervorum. Vindob. 1780, 8vo. Al. Monro. l. c.

‡.
[Seite 124]

See Reil in the Archiv für Physiologie. T. vii. p. 189.

*.
[Seite 125]

The Cartesian hypothesis appeared to receive some weight from the
dissection of maniacs, in whom the pineal gland was found full of calca-
reous substances. But more careful observation shewed, that, after the
twelfth year, it was generally filled with a pearly sand, in the healthiest
persons, though very seldom in animals Sömmering de lapillas vel prope
vel infra gland. pin. sitis, s. de acervulo cerebri.
Mogunt. 1785. 8vo.

*.
[Seite 126]

The prerogative of this part was ably refuted by Zinn. Exp. circa
corpus callosum, cerebellum, duram meningem, in vivis animalibus instit.

Gott. 1749. 4to.

*.
[Seite 127]

See Michelitz’s Scrutinium Hypotheseos Spirituum Animalium. Prag.
1782, 8vo.

†.
[Seite 127]

Fr. Al. Von Humboldt über die gereizte Muskel und Nerven fafer. Posen.
1797, ii. vol. 8vo.

J. W. Ritter, Beweis dass ein beständiger Galvanismus den Lebensprocess im
Thierreiche begleite.
Vinar. 1798, 8vo.

*.
[Seite 128]

J. Heineken, Ideen u. Beobachtungen den thierischen Magnetismus betres-
send.
Brem. 1800. 8vo.

†.
[Seite 128]

v. Humboldt and Heineken. ll. cc.

‡.
[Seite 128]

Dav. Hartley’s Observat. on Man, his Frame, his Duty, and his Expecta-
tions. Lond.
1749, 8vo. vol. i. p. 44.

§.
[Seite 128]

Queries at the end of his Optics, Qu. 23, p. 355, Lond. 1789, 8vo.

ǁ.
[Seite 128]

Er. Darwin has carried these opinions of Hartley still farther. Zoono-
mia,
T. i.

*.
[Seite 129]

Bichat Traité des Membranes.

*.
[Seite 130]

Anatomie et Physiologie du Systeme nerveux, par Gall et Spurzheim, and
Physiognomical System by Spurzheim.

*.
[Seite 131]

Experiments, &c. by A.P. Wilson Philip, M.D. and Wm. Clift, Philos.
Trans.
1815.

†.
[Seite 131]

Le Gallois, Sur le Principe de la Vie, and Wilson Philip, l. c.

‡.
[Seite 131]

Wilson Philip, l. c. Probably by excessive stimulus, as the voluntary
muscles are afterwards insensible to stimuli, although after a mere division
of their nerves, they retain their excitability.

*.
[Seite 132]

Le Gallois, l. c.

*.
[Seite 133]

J. De Gorter’s Exercitationes Medicae, iv. Amst. 1737, 4to.

†.
[Seite 133]

Consult Rol. Martin in the Schwed Abhandl. Vol. xxxix. 1777.

G. Bew in the Memoirs of a Society of Manchester, Vol. i. p. 159.

Ch. Hutton’s Mathematical Dictionary, Vol. i. p. 214.

*.
[Seite 134]

F. de Riet, De Organo Tactus, L.B. 1743, 4to. reprinted in Haller’s An-
atomical Collection, T. iv.

†.
[Seite 134]

Dav. Corn. de Courcelles’ Icones Musculor. Capitis, Tab. i. f. 2, 3.

‡.
[Seite 134]

B.S. Albinus’ Annotat. Academ. L. iii. tab. iv. fig. 1, 2.

§.
[Seite 134]

Ruysch’s Thesaur. Anat. iii. tab. iv. f. i. Thes. vii. tab. ii. fig. 5.

B.S. Albinus, l. c. L. vi. Tab. ii. fig. 3, 4.

ǁ.
[Seite 134]

Grew in the Philos. Trans. n. 159.

¶.
[Seite 134]

B.S. Albinus. Annotat. Acad. L. ii. tab. vii. f. 4. 5. 6.

**.
[Seite 134]

Namely simiae, papiones, cercopitheci and lemures the apices of whose
fingers in their four hands are very soft and marked, as in the human subject,
with spiral lines.

Physiologists have disputed whether the sense of touch is bestowed on
any besides man and the quadrumana. In determining this controversy
we must recollect what was formerly said (81) concerning the differ-
ence of constitution according to the mode of living. On one hand, I would
[Seite 135] grant to both parties, that the snowy hands of a delicate girl must enjoy a
much more exquisite sense of touch, than what I called the fingers of ani-
mals. But, on the other hand, I have frequently seen simiae and papiones pos-
sessing much softer fingers, and using these fingers to explore surfaces
much more dexterously, than many barbarous nations and innumerable per-
sons among the lower orders of Europeans, whose hands have become har-
dened from labour.

*.
[Seite 135]

B.S. Albinus De Habitu et Colore Aethiopum, fig. 3.

*.
[Seite 136]

Grew’s Anatomy of Plants, p. 284, sq.

Petr. Luchtmans De Saporibus et Gustu. L.B. 1758. 4to. p. 58, sqq.

J. Gottl. Leidenfrost De sensu qui in faucibus est, ob eo qui in lin lingua exer-
citur, diverso.
Duisb. 1771, 4to.

†.
[Seite 136]

Sömmering’s Icones Organorum Humanorum Gustus. Francof. 1808, fol.

‡.
[Seite 136]

In dogs and sheep with variously coloured skin, I have commonly found
the reticulum of the tongue and fauces also of various colours.

*.
[Seite 137]

Consult Just. Schrader’s Observat. et Histor. from Harvey’s book De
Generation Animalium,
p. 186.

†.
[Seite 137]

Morgagni’s Adversar. Anat. Prima. Tab. i.

‡.
[Seite 137]

Ruysch’s Thesaur. Anat. 1. tab. iv. fig. 6.

B.S. Albinus’ Annotat. Acad. L. i. tab. i. f. 6–11.

§.
[Seite 137]

Consult Haller’s excellent description of the tongue of a living man, in
the Diction. Encyclypedique. Yverdon edition. Vol. xxii. p. 28.

ǁ.
[Seite 137]

J.F. Meckel De Quinto pare Nervorum Cerebri. Gotting. 1748. 4to. p.
97. fig. 1. n. 80.

**.
[Seite 137]

J.F.W. Meckel De Nono pare Nervorum Cerebri. Gotting. 1777, 4to.

††.
[Seite 137]

See Haller’s Icon. Anatom. fasc. ii. tab. 1. letter g.

Monro on the Nervous System. Tab. xxiv.

‡‡.
[Seite 137]

Bellini. Gustus Organum novisiime deprehensum. Bonon. 1665. 12mo.

*.
[Seite 139]

Conr. Vict. Schneider De Osse Cribriformi et Sensu ac Organo Odora-
tus.
Witteb. 1655, 12mo.

This classical work forms an epoch in physiological history, not only be-
cause it is the first accurate treatise on the function of smell, but because it
put an end to the visionary doctrine of the organ of smell being the emunc-
tory of the brain.

†.
[Seite 139]

Sömmerring’s Icones Organorum Humanorum Olfactus, Francof. 1810,
fol.

‡.
[Seite 139]

Haller’s Icones. Anat. fasc. iv. tab. ii.

Duverney’s Oeuvres Anatom. Vol. i. tab. xiv.

Santorini’s Tab. Posthum, iv.

*.
[Seite 140]

In my Prolus. de Sinibus Frontal. Gotting. 1779. 4to. I have brought
forward many arguments from osteogony, comparative anatomy, and patho-
logical phenomena, to prove that these sinuses contribute indeed to the smell,
but little or nothing to voice and language, as was believed by many phy-
siologists.

†.
[Seite 140]

Metzger Nervorum Primi Paris Historia. Argent. 1766, 4to. reprint-
ed in Sandifort’s Thesaurus. Vol. iii.

Scarpa, Anatomic Annotat. L. ii. tab. i. ii.

*.
[Seite 141]

This is shewn by pathological dissection and comparative anatomy.
Thus in Loder’s Observ. Tumoris Scirrhosi in Basi Cranii Reperti. Jen.
1779, 4to. is a case of anosmia, following a compression of the first pair by a
scirrhus. We are taught, by comparative anatomy, that in the most saga-
cious mammalia, v.c. elephants, bears, dogs, bisulcus ruminants, hedgehogs,
&c. the horizontal plate of the cribriform bone is very large, and perforated
by an infinity of small canals, each of which contains a filament of the olfac-
tory nerve.

†.
[Seite 141]

While animals of the most acute smell have the nasal organs most ex-
tensively evolved, precisely the same holds in regard to some barbarous na-
tions. For instance, in the head of the North American Indian, (a leader of
his nation, and executed at Philadelphia about fifty years since), which I
have given in the First Decade of my Collection of the Crania of different Na-
tions,
illustrated by nine plates, the internal nares are of an extraordinary size,
so that the middle conchae, for instance, are inflated into immense bullae;
and the sinuses, first described by Santorini, which are contained in them, I
never, in any other instance, found so large.

The nearest to these, in point of magnitude, are the internal nares of the
Ethiopians, from among whom I have seven heads now before me, very diffe-
rent from each other, but each possessing a nasal organ, much larger than we
find it described by Sömmerring to be in that nation, über die körperl. Vers-
chiedenh des Negers, &c.
p. 22.

[Seite 142]

These anatomical observations accord with the accounts given by most re-
spectable travellers concerning the wonderful acuteness of smell possessed
by these savages.

Respecting the North American Indians, consult among others Urlsperger.
Nachr. von der Grossbritann. Colonie Salzburg. Emigranten in America. Vol.
i. p. 862.

Respecting the Ethiopians, the Journal des Scavans, 1667, p. 60.

*.
[Seite 142]

See Alibert on the Medical power of Odors, in the Mem. de la Soc. Me-
dicale.
T. i. p. 44.

†.
[Seite 142]

Emile. T. i. p. 367.

‡.
[Seite 142]

Respecting the power of smell over the disposition and the propensities,
consult Benj. Rush, in the Medical Inquiries and Observations. Vol. ii. p. 34.

*.
[Seite 143]

Sömmerring. Abildung des Menschlichen Hörorgans. Francof. 1806,
fol.

†.
[Seite 143]

B.S. Albinus. Annotat. Academ. L. vi. tab. iv.

‡.
[Seite 143]

J. Rhodius ad Scribon. Largum. p. 44, sq.

J.Alb. Fabricius De Hominibus ortu non differentibus. Opuscul. p. 441.

Ch. Collignon’s Miscellaneous Works. Camb. 1786, 4to. p. 25, sq.

§.
[Seite 143]

Consult J. Haygarth in the Med. Obs. and Inquires, vol. iv. p. 198, sq.

ǁ.
[Seite 143]

The existence of a fourth bone (called Lenticular) commonly believed
from the time of Franc. Sylvius, I have disproved at length in my Osteology,
p, 155. et seq. edit. 2. It is wanting in the greater number of perfect ex-
amples from adults.

*.
[Seite 144]

Saunder’s Anatomy of the human ear. Lond. 1801, fol. vol. i. ii.

†.
[Seite 144]

Scarpa De Structura Fenestrae Rotundae, &c. Mutin. 1772, 8vo.

‡.
[Seite 144]

Comparative anatomy renders it most probable that the Eustachian tube
is subservient to the action of the membrana tympani. It is found in all red-
blooded animals which possess a membrana tympani; but is wanting in fishes
which are destisute of this membrane. The different opinions respecting its
use may be found in Keil’s Archiv. für die Physiol. T. ii. p. 18. iii. p. 165. iv.
p. 105. viii. p. 67. ix. p. 320.

*.
[Seite 145]

Scarpa’s Disquisitiones Anatomicae de Auditu et Olfactu. Tab. iv. fig.
5. tab. vii. fig. 5.

†.
[Seite 145]

Cotunni De Aqueductibus auris Humanae. Neap. 1760, 4to.

‡.
[Seite 145]

Ph. Fr. Meckel De Labyrinthi auris Contentis. Argen. 1777, 4to.

§.
[Seite 145]

Fallopius’ Observ. Anat. p. 27, sq. Venet. 1561, 8vo.

¶.
[Seite 145]

Brendelii Analecta de Concha auris Humanae. Gotting. 1747, 4to.

The same, De Auditu in Apice Conchae, ib. eod. 4to.

**.
[Seite 145]

Consult Zinn’s Observ. Botan. Gotting. 1753, 4to. p. 31, sq.

Scarpa l. c. tab. viii. fig. 1. 2.

*.
[Seite 146]

B.S. Albini Tabulae Muscul. tab. xi. fig. 29.

†.
[Seite 146]

Eustach. De Auditus Organ. p. 157.

Caldani. Institut. Physiol. 245, sq.

‡.
[Seite 146]

T. Fr. Meckel De Quinto pare Nervorum Cerebri. fig. 1. x. 71.

Leop. M.A. Caldani on the Office of the chorda tympani, in the Saggi
dell’ Acad. di Padova,
T. ii.

§.
[Seite 146]

Cotunni. l. c. §. lxxxviii. Marherr’s Proaelect. in Boerhaavii Inst. Vol.
iii. p. 343.

*.
[Seite 147]

Sömmerring. Abbildungen des Menschlichen Auges. Francfort,
1801, fol.

†.
[Seite 147]

Ad. Jul. Rose Be Morbis Corneae ex Fabrica ejus Declaratis. Lips.
1767, 4to.

G.H. Gerson De Forma Corneae Deque Singularis Visus Phaenomeno.
Gotting. 1810, 4to.